diff --git a/src/applications/search/controller/PhabricatorApplicationSearchController.php b/src/applications/search/controller/PhabricatorApplicationSearchController.php
index a5c58aac7f..f0bf9bb365 100644
--- a/src/applications/search/controller/PhabricatorApplicationSearchController.php
+++ b/src/applications/search/controller/PhabricatorApplicationSearchController.php
@@ -1,953 +1,985 @@
 <?php
 
 final class PhabricatorApplicationSearchController
   extends PhabricatorSearchBaseController {
 
   private $searchEngine;
   private $navigation;
   private $queryKey;
   private $preface;
 
   public function setPreface($preface) {
     $this->preface = $preface;
     return $this;
   }
 
   public function getPreface() {
     return $this->preface;
   }
 
   public function setQueryKey($query_key) {
     $this->queryKey = $query_key;
     return $this;
   }
 
   protected function getQueryKey() {
     return $this->queryKey;
   }
 
   public function setNavigation(AphrontSideNavFilterView $navigation) {
     $this->navigation = $navigation;
     return $this;
   }
 
   protected function getNavigation() {
     return $this->navigation;
   }
 
   public function setSearchEngine(
     PhabricatorApplicationSearchEngine $search_engine) {
     $this->searchEngine = $search_engine;
     return $this;
   }
 
   protected function getSearchEngine() {
     return $this->searchEngine;
   }
 
   protected function validateDelegatingController() {
     $parent = $this->getDelegatingController();
 
     if (!$parent) {
       throw new Exception(
         pht('You must delegate to this controller, not invoke it directly.'));
     }
 
     $engine = $this->getSearchEngine();
     if (!$engine) {
       throw new PhutilInvalidStateException('setEngine');
     }
 
     $engine->setViewer($this->getRequest()->getUser());
 
     $parent = $this->getDelegatingController();
   }
 
   public function processRequest() {
     $this->validateDelegatingController();
 
     $query_action = $this->getRequest()->getURIData('queryAction');
     if ($query_action == 'export') {
       return $this->processExportRequest();
     }
 
     $key = $this->getQueryKey();
     if ($key == 'edit') {
       return $this->processEditRequest();
     } else {
       return $this->processSearchRequest();
     }
   }
 
   private function processSearchRequest() {
     $parent = $this->getDelegatingController();
     $request = $this->getRequest();
     $user = $request->getUser();
     $engine = $this->getSearchEngine();
     $nav = $this->getNavigation();
     if (!$nav) {
       $nav = $this->buildNavigation();
     }
 
     if ($request->isFormPost()) {
       $saved_query = $engine->buildSavedQueryFromRequest($request);
       $engine->saveQuery($saved_query);
       return id(new AphrontRedirectResponse())->setURI(
         $engine->getQueryResultsPageURI($saved_query->getQueryKey()).'#R');
     }
 
     $named_query = null;
     $run_query = true;
     $query_key = $this->queryKey;
     if ($this->queryKey == 'advanced') {
       $run_query = false;
       $query_key = $request->getStr('query');
     } else if (!strlen($this->queryKey)) {
       $found_query_data = false;
 
       if ($request->isHTTPGet() || $request->isQuicksand()) {
         // If this is a GET request and it has some query data, don't
         // do anything unless it's only before= or after=. We'll build and
         // execute a query from it below. This allows external tools to build
         // URIs like "/query/?users=a,b".
         $pt_data = $request->getPassthroughRequestData();
 
         $exempt = array(
           'before' => true,
           'after' => true,
           'nux' => true,
           'overheated' => true,
         );
 
         foreach ($pt_data as $pt_key => $pt_value) {
           if (isset($exempt[$pt_key])) {
             continue;
           }
 
           $found_query_data = true;
           break;
         }
       }
 
       if (!$found_query_data) {
         // Otherwise, there's no query data so just run the user's default
         // query for this application.
         $query_key = $engine->getDefaultQueryKey();
       }
     }
 
     if ($engine->isBuiltinQuery($query_key)) {
       $saved_query = $engine->buildSavedQueryFromBuiltin($query_key);
       $named_query = idx($engine->loadEnabledNamedQueries(), $query_key);
     } else if ($query_key) {
       $saved_query = id(new PhabricatorSavedQueryQuery())
         ->setViewer($user)
         ->withQueryKeys(array($query_key))
         ->executeOne();
 
       if (!$saved_query) {
         return new Aphront404Response();
       }
 
       $named_query = idx($engine->loadEnabledNamedQueries(), $query_key);
     } else {
       $saved_query = $engine->buildSavedQueryFromRequest($request);
 
       // Save the query to generate a query key, so "Save Custom Query..." and
       // other features like Maniphest's "Export..." work correctly.
       $engine->saveQuery($saved_query);
     }
 
     $nav->selectFilter(
       'query/'.$saved_query->getQueryKey(),
       'query/advanced');
 
     $form = id(new AphrontFormView())
       ->setUser($user)
       ->setAction($request->getPath());
 
     $engine->buildSearchForm($form, $saved_query);
 
     $errors = $engine->getErrors();
     if ($errors) {
       $run_query = false;
     }
 
     $submit = id(new AphrontFormSubmitControl())
       ->setValue(pht('Search'));
 
     if ($run_query && !$named_query && $user->isLoggedIn()) {
       $save_button = id(new PHUIButtonView())
         ->setTag('a')
         ->setHref('/search/edit/key/'.$saved_query->getQueryKey().'/')
         ->setText(pht('Save Query'))
         ->setIcon('fa-floppy-o');
       $submit->addButton($save_button);
     }
 
     // TODO: A "Create Dashboard Panel" action goes here somewhere once
     // we sort out T5307.
 
     $form->appendChild($submit);
     $body = array();
 
     if ($this->getPreface()) {
       $body[] = $this->getPreface();
     }
 
     if ($named_query) {
       $title = $named_query->getQueryName();
     } else {
       $title = pht('Advanced Search');
     }
 
     $header = id(new PHUIHeaderView())
       ->setHeader($title)
       ->setProfileHeader(true);
 
     $box = id(new PHUIObjectBoxView())
       ->setHeader($header)
       ->addClass('application-search-results');
 
     if ($run_query || $named_query) {
       $box->setShowHide(
         pht('Edit Query'),
         pht('Hide Query'),
         $form,
         $this->getApplicationURI('query/advanced/?query='.$query_key),
         (!$named_query ? true : false));
     } else {
       $box->setForm($form);
     }
 
     $body[] = $box;
     $more_crumbs = null;
 
     if ($run_query) {
       $exec_errors = array();
 
       $box->setAnchor(
         id(new PhabricatorAnchorView())
           ->setAnchorName('R'));
 
       try {
         $engine->setRequest($request);
 
         $query = $engine->buildQueryFromSavedQuery($saved_query);
 
         $pager = $engine->newPagerForSavedQuery($saved_query);
         $pager->readFromRequest($request);
 
         $objects = $engine->executeQuery($query, $pager);
 
         $force_nux = $request->getBool('nux');
         if (!$objects || $force_nux) {
           $nux_view = $this->renderNewUserView($engine, $force_nux);
         } else {
           $nux_view = null;
         }
 
         $is_overflowing =
           $pager->willShowPagingControls() &&
           $engine->getResultBucket($saved_query);
 
         $force_overheated = $request->getBool('overheated');
         $is_overheated = $query->getIsOverheated() || $force_overheated;
 
         if ($nux_view) {
           $box->appendChild($nux_view);
         } else {
           $list = $engine->renderResults($objects, $saved_query);
 
           if (!($list instanceof PhabricatorApplicationSearchResultView)) {
             throw new Exception(
               pht(
                 'SearchEngines must render a "%s" object, but this engine '.
                 '(of class "%s") rendered something else.',
                 'PhabricatorApplicationSearchResultView',
                 get_class($engine)));
           }
 
           if ($list->getObjectList()) {
             $box->setObjectList($list->getObjectList());
           }
           if ($list->getTable()) {
             $box->setTable($list->getTable());
           }
           if ($list->getInfoView()) {
             $box->setInfoView($list->getInfoView());
           }
 
           if ($is_overflowing) {
             $box->appendChild($this->newOverflowingView());
           }
 
           if ($list->getContent()) {
             $box->appendChild($list->getContent());
           }
 
           if ($is_overheated) {
             $box->appendChild($this->newOverheatedView($objects));
           }
 
           $result_header = $list->getHeader();
           if ($result_header) {
             $box->setHeader($result_header);
             $header = $result_header;
           }
 
           $actions = $list->getActions();
           if ($actions) {
             foreach ($actions as $action) {
               $header->addActionLink($action);
             }
           }
 
           $use_actions = $engine->newUseResultsActions($saved_query);
 
           // TODO: Eventually, modularize all this stuff.
           $builtin_use_actions = $this->newBuiltinUseActions();
           if ($builtin_use_actions) {
             foreach ($builtin_use_actions as $builtin_use_action) {
               $use_actions[] = $builtin_use_action;
             }
           }
 
           if ($use_actions) {
             $use_dropdown = $this->newUseResultsDropdown(
               $saved_query,
               $use_actions);
             $header->addActionLink($use_dropdown);
           }
 
           $more_crumbs = $list->getCrumbs();
 
           if ($pager->willShowPagingControls()) {
             $pager_box = id(new PHUIBoxView())
               ->setColor(PHUIBoxView::GREY)
               ->addClass('application-search-pager')
               ->appendChild($pager);
             $body[] = $pager_box;
           }
         }
       } catch (PhabricatorTypeaheadInvalidTokenException $ex) {
         $exec_errors[] = pht(
           'This query specifies an invalid parameter. Review the '.
           'query parameters and correct errors.');
       } catch (PhutilSearchQueryCompilerSyntaxException $ex) {
         $exec_errors[] = $ex->getMessage();
       } catch (PhabricatorSearchConstraintException $ex) {
         $exec_errors[] = $ex->getMessage();
       }
 
       // The engine may have encountered additional errors during rendering;
       // merge them in and show everything.
       foreach ($engine->getErrors() as $error) {
         $exec_errors[] = $error;
       }
 
       $errors = $exec_errors;
     }
 
     if ($errors) {
       $box->setFormErrors($errors, pht('Query Errors'));
     }
 
     $crumbs = $parent
       ->buildApplicationCrumbs()
       ->setBorder(true);
 
     if ($more_crumbs) {
       $query_uri = $engine->getQueryResultsPageURI($saved_query->getQueryKey());
       $crumbs->addTextCrumb($title, $query_uri);
 
       foreach ($more_crumbs as $crumb) {
         $crumbs->addCrumb($crumb);
       }
     } else {
       $crumbs->addTextCrumb($title);
     }
 
     require_celerity_resource('application-search-view-css');
 
     return $this->newPage()
       ->setApplicationMenu($this->buildApplicationMenu())
       ->setTitle(pht('Query: %s', $title))
       ->setCrumbs($crumbs)
       ->setNavigation($nav)
       ->addClass('application-search-view')
       ->appendChild($body);
   }
 
   private function processExportRequest() {
     $viewer = $this->getViewer();
     $engine = $this->getSearchEngine();
     $request = $this->getRequest();
 
     if (!$this->canExport()) {
       return new Aphront404Response();
     }
 
     $query_key = $this->getQueryKey();
     if ($engine->isBuiltinQuery($query_key)) {
       $saved_query = $engine->buildSavedQueryFromBuiltin($query_key);
     } else if ($query_key) {
       $saved_query = id(new PhabricatorSavedQueryQuery())
         ->setViewer($viewer)
         ->withQueryKeys(array($query_key))
         ->executeOne();
     } else {
       $saved_query = null;
     }
 
     if (!$saved_query) {
       return new Aphront404Response();
     }
 
     $cancel_uri = $engine->getQueryResultsPageURI($query_key);
 
     $named_query = idx($engine->loadEnabledNamedQueries(), $query_key);
 
     if ($named_query) {
       $filename = $named_query->getQueryName();
       $sheet_title = $named_query->getQueryName();
     } else {
       $filename = $engine->getResultTypeDescription();
       $sheet_title = $engine->getResultTypeDescription();
     }
     $filename = phutil_utf8_strtolower($filename);
     $filename = PhabricatorFile::normalizeFileName($filename);
 
-    $formats = PhabricatorExportFormat::getAllEnabledExportFormats();
-    $format_options = mpull($formats, 'getExportFormatName');
+    $all_formats = PhabricatorExportFormat::getAllExportFormats();
+
+    $available_options = array();
+    $unavailable_options = array();
+    $formats = array();
+    $unavailable_formats = array();
+    foreach ($all_formats as $key => $format) {
+      if ($format->isExportFormatEnabled()) {
+        $available_options[$key] = $format->getExportFormatName();
+        $formats[$key] = $format;
+      } else {
+        $unavailable_options[$key] = pht(
+          '%s (Not Available)',
+          $format->getExportFormatName());
+        $unavailable_formats[$key] = $format;
+      }
+    }
+    $format_options = $available_options + $unavailable_options;
 
     // Try to default to the format the user used last time. If you just
     // exported to Excel, you probably want to export to Excel again.
     $format_key = $this->readExportFormatPreference();
     if (!isset($formats[$format_key])) {
       $format_key = head_key($format_options);
     }
 
     $errors = array();
 
     $e_format = null;
     if ($request->isFormPost()) {
       $format_key = $request->getStr('format');
+
+      if (isset($unavailable_formats[$format_key])) {
+        $unavailable = $unavailable_formats[$format_key];
+        $instructions = $unavailable->getInstallInstructions();
+
+        $markup = id(new PHUIRemarkupView($viewer, $instructions))
+          ->setRemarkupOption(
+            PHUIRemarkupView::OPTION_PRESERVE_LINEBREAKS,
+            false);
+
+        return $this->newDialog()
+          ->setTitle(pht('Export Format Not Available'))
+          ->appendChild($markup)
+          ->addCancelButton($cancel_uri, pht('Done'));
+      }
+
       $format = idx($formats, $format_key);
 
       if (!$format) {
         $e_format = pht('Invalid');
         $errors[] = pht('Choose a valid export format.');
       }
 
       if (!$errors) {
         $this->writeExportFormatPreference($format_key);
 
         $query = $engine->buildQueryFromSavedQuery($saved_query);
 
         // NOTE: We aren't reading the pager from the request. Exports always
         // affect the entire result set.
         $pager = $engine->newPagerForSavedQuery($saved_query);
         $pager->setPageSize(0x7FFFFFFF);
 
         $objects = $engine->executeQuery($query, $pager);
 
         $extension = $format->getFileExtension();
         $mime_type = $format->getMIMEContentType();
         $filename = $filename.'.'.$extension;
 
         $format = id(clone $format)
           ->setViewer($viewer)
           ->setTitle($sheet_title);
 
         $export_data = $engine->newExport($objects);
         $objects = array_values($objects);
 
         $field_list = $engine->newExportFieldList();
         $field_list = mpull($field_list, null, 'getKey');
 
         $format->addHeaders($field_list);
         for ($ii = 0; $ii < count($objects); $ii++) {
           $format->addObject($objects[$ii], $field_list, $export_data[$ii]);
         }
 
         $export_result = $format->newFileData();
 
         // We have all the data in one big string and aren't actually
         // streaming it, but pretending that we are allows us to actviate
         // the chunk engine and store large files.
         $iterator = new ArrayIterator(array($export_result));
 
         $source = id(new PhabricatorIteratorFileUploadSource())
           ->setName($filename)
           ->setViewPolicy(PhabricatorPolicies::POLICY_NOONE)
           ->setMIMEType($mime_type)
           ->setRelativeTTL(phutil_units('60 minutes in seconds'))
           ->setAuthorPHID($viewer->getPHID())
           ->setIterator($iterator);
 
         $file = $source->uploadFile();
 
         return $this->newDialog()
           ->setTitle(pht('Download Results'))
           ->appendParagraph(
             pht('Click the download button to download the exported data.'))
           ->addCancelButton($cancel_uri, pht('Done'))
           ->setSubmitURI($file->getDownloadURI())
           ->setDisableWorkflowOnSubmit(true)
           ->addSubmitButton(pht('Download Data'));
       }
     }
 
     $export_form = id(new AphrontFormView())
       ->setViewer($viewer)
       ->appendControl(
         id(new AphrontFormSelectControl())
           ->setName('format')
           ->setLabel(pht('Format'))
           ->setError($e_format)
           ->setValue($format_key)
           ->setOptions($format_options));
 
     return $this->newDialog()
       ->setTitle(pht('Export Results'))
       ->setErrors($errors)
       ->appendForm($export_form)
       ->addCancelButton($cancel_uri)
       ->addSubmitButton(pht('Continue'));
   }
 
   private function processEditRequest() {
     $parent = $this->getDelegatingController();
     $request = $this->getRequest();
     $viewer = $request->getUser();
     $engine = $this->getSearchEngine();
 
     $nav = $this->getNavigation();
     if (!$nav) {
       $nav = $this->buildNavigation();
     }
 
     $named_queries = $engine->loadAllNamedQueries();
 
     $can_global = $viewer->getIsAdmin();
 
     $groups = array(
       'personal' => array(
         'name' => pht('Personal Saved Queries'),
         'items' => array(),
         'edit' => true,
       ),
       'global' => array(
         'name' => pht('Global Saved Queries'),
         'items' => array(),
         'edit' => $can_global,
       ),
     );
 
     foreach ($named_queries as $named_query) {
       if ($named_query->isGlobal()) {
         $group = 'global';
       } else {
         $group = 'personal';
       }
 
       $groups[$group]['items'][] = $named_query;
     }
 
     $default_key = $engine->getDefaultQueryKey();
 
     $lists = array();
     foreach ($groups as $group) {
       $lists[] = $this->newQueryListView(
         $group['name'],
         $group['items'],
         $default_key,
         $group['edit']);
     }
 
     $crumbs = $parent
       ->buildApplicationCrumbs()
       ->addTextCrumb(pht('Saved Queries'), $engine->getQueryManagementURI())
       ->setBorder(true);
 
     $nav->selectFilter('query/edit');
 
     $header = id(new PHUIHeaderView())
       ->setHeader(pht('Saved Queries'))
       ->setProfileHeader(true);
 
     $view = id(new PHUITwoColumnView())
       ->setHeader($header)
       ->setFooter($lists);
 
     return $this->newPage()
       ->setApplicationMenu($this->buildApplicationMenu())
       ->setTitle(pht('Saved Queries'))
       ->setCrumbs($crumbs)
       ->setNavigation($nav)
       ->appendChild($view);
   }
 
   private function newQueryListView(
     $list_name,
     array $named_queries,
     $default_key,
     $can_edit) {
 
     $engine = $this->getSearchEngine();
     $viewer = $this->getViewer();
 
     $list = id(new PHUIObjectItemListView())
       ->setViewer($viewer);
 
     if ($can_edit) {
       $list_id = celerity_generate_unique_node_id();
       $list->setID($list_id);
 
       Javelin::initBehavior(
         'search-reorder-queries',
         array(
           'listID' => $list_id,
           'orderURI' => '/search/order/'.get_class($engine).'/',
         ));
     }
 
     foreach ($named_queries as $named_query) {
       $class = get_class($engine);
       $key = $named_query->getQueryKey();
 
       $item = id(new PHUIObjectItemView())
         ->setHeader($named_query->getQueryName())
         ->setHref($engine->getQueryResultsPageURI($key));
 
       if ($named_query->getIsDisabled()) {
         if ($can_edit) {
           $item->setDisabled(true);
         } else {
           // If an item is disabled and you don't have permission to edit it,
           // just skip it.
           continue;
         }
       }
 
       if ($can_edit) {
         if ($named_query->getIsBuiltin() && $named_query->getIsDisabled()) {
           $icon = 'fa-plus';
           $disable_name = pht('Enable');
         } else {
           $icon = 'fa-times';
           if ($named_query->getIsBuiltin()) {
             $disable_name = pht('Disable');
           } else {
             $disable_name = pht('Delete');
           }
         }
 
         if ($named_query->getID()) {
           $disable_href = '/search/delete/id/'.$named_query->getID().'/';
         } else {
           $disable_href = '/search/delete/key/'.$key.'/'.$class.'/';
         }
 
         $item->addAction(
           id(new PHUIListItemView())
             ->setIcon($icon)
             ->setHref($disable_href)
             ->setRenderNameAsTooltip(true)
             ->setName($disable_name)
             ->setWorkflow(true));
       }
 
       $default_disabled = $named_query->getIsDisabled();
       $default_icon = 'fa-thumb-tack';
 
       if ($default_key === $key) {
         $default_color = 'green';
       } else {
         $default_color = null;
       }
 
       $item->addAction(
         id(new PHUIListItemView())
           ->setIcon("{$default_icon} {$default_color}")
           ->setHref('/search/default/'.$key.'/'.$class.'/')
           ->setRenderNameAsTooltip(true)
           ->setName(pht('Make Default'))
           ->setWorkflow(true)
           ->setDisabled($default_disabled));
 
       if ($can_edit) {
         if ($named_query->getIsBuiltin()) {
           $edit_icon = 'fa-lock lightgreytext';
           $edit_disabled = true;
           $edit_name = pht('Builtin');
           $edit_href = null;
         } else {
           $edit_icon = 'fa-pencil';
           $edit_disabled = false;
           $edit_name = pht('Edit');
           $edit_href = '/search/edit/id/'.$named_query->getID().'/';
         }
 
         $item->addAction(
           id(new PHUIListItemView())
             ->setIcon($edit_icon)
             ->setHref($edit_href)
             ->setRenderNameAsTooltip(true)
             ->setName($edit_name)
             ->setDisabled($edit_disabled));
       }
 
       $item->setGrippable($can_edit);
       $item->addSigil('named-query');
       $item->setMetadata(
         array(
           'queryKey' => $named_query->getQueryKey(),
         ));
 
       $list->addItem($item);
     }
 
     $list->setNoDataString(pht('No saved queries.'));
 
     return id(new PHUIObjectBoxView())
       ->setHeaderText($list_name)
       ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
       ->setObjectList($list);
   }
 
   public function buildApplicationMenu() {
     $menu = $this->getDelegatingController()
       ->buildApplicationMenu();
 
     if ($menu instanceof PHUIApplicationMenuView) {
       $menu->setSearchEngine($this->getSearchEngine());
     }
 
     return $menu;
   }
 
   private function buildNavigation() {
     $viewer = $this->getViewer();
     $engine = $this->getSearchEngine();
 
     $nav = id(new AphrontSideNavFilterView())
       ->setUser($viewer)
       ->setBaseURI(new PhutilURI($this->getApplicationURI()));
 
     $engine->addNavigationItems($nav->getMenu());
 
     return $nav;
   }
 
   private function renderNewUserView(
     PhabricatorApplicationSearchEngine $engine,
     $force_nux) {
 
     // Don't render NUX if the user has clicked away from the default page.
     if (strlen($this->getQueryKey())) {
       return null;
     }
 
     // Don't put NUX in panels because it would be weird.
     if ($engine->isPanelContext()) {
       return null;
     }
 
     // Try to render the view itself first, since this should be very cheap
     // (just returning some text).
     $nux_view = $engine->renderNewUserView();
 
     if (!$nux_view) {
       return null;
     }
 
     $query = $engine->newQuery();
     if (!$query) {
       return null;
     }
 
     // Try to load any object at all. If we can, the application has seen some
     // use so we just render the normal view.
     if (!$force_nux) {
       $object = $query
         ->setViewer(PhabricatorUser::getOmnipotentUser())
         ->setLimit(1)
         ->execute();
       if ($object) {
         return null;
       }
     }
 
     return $nux_view;
   }
 
   private function newUseResultsDropdown(
     PhabricatorSavedQuery $query,
     array $dropdown_items) {
 
     $viewer = $this->getViewer();
 
     $action_list = id(new PhabricatorActionListView())
       ->setViewer($viewer);
     foreach ($dropdown_items as $dropdown_item) {
       $action_list->addAction($dropdown_item);
     }
 
     return id(new PHUIButtonView())
       ->setTag('a')
       ->setHref('#')
       ->setText(pht('Use Results'))
       ->setIcon('fa-bars')
       ->setDropdownMenu($action_list)
       ->addClass('dropdown');
   }
 
   private function newOverflowingView() {
     $message = pht(
       'The query matched more than one page of results. Results are '.
       'paginated before bucketing, so later pages may contain additional '.
       'results in any bucket.');
 
     return id(new PHUIInfoView())
       ->setSeverity(PHUIInfoView::SEVERITY_WARNING)
       ->setFlush(true)
       ->setTitle(pht('Buckets Overflowing'))
       ->setErrors(
         array(
           $message,
         ));
   }
 
   private function newOverheatedView(array $results) {
     if ($results) {
       $message = pht(
         'Most objects matching your query are not visible to you, so '.
         'filtering results is taking a long time. Only some results are '.
         'shown. Refine your query to find results more quickly.');
     } else {
       $message = pht(
         'Most objects matching your query are not visible to you, so '.
         'filtering results is taking a long time. Refine your query to '.
         'find results more quickly.');
     }
 
     return id(new PHUIInfoView())
       ->setSeverity(PHUIInfoView::SEVERITY_WARNING)
       ->setFlush(true)
       ->setTitle(pht('Query Overheated'))
       ->setErrors(
         array(
           $message,
         ));
   }
 
   private function newBuiltinUseActions() {
     $actions = array();
     $request = $this->getRequest();
     $viewer = $request->getUser();
 
     $is_dev = PhabricatorEnv::getEnvConfig('phabricator.developer-mode');
 
     $engine = $this->getSearchEngine();
     $engine_class = get_class($engine);
     $query_key = $this->getQueryKey();
     if (!$query_key) {
       $query_key = $engine->getDefaultQueryKey();
     }
 
     $can_use = $engine->canUseInPanelContext();
     $is_installed = PhabricatorApplication::isClassInstalledForViewer(
       'PhabricatorDashboardApplication',
       $viewer);
 
     if ($can_use && $is_installed) {
       $actions[] = id(new PhabricatorActionView())
         ->setIcon('fa-dashboard')
         ->setName(pht('Add to Dashboard'))
         ->setWorkflow(true)
         ->setHref("/dashboard/panel/install/{$engine_class}/{$query_key}/");
     }
 
     if ($this->canExport()) {
       $export_uri = $engine->getExportURI($query_key);
       $actions[] = id(new PhabricatorActionView())
         ->setIcon('fa-download')
         ->setName(pht('Export Data'))
         ->setWorkflow(true)
         ->setHref($export_uri);
     }
 
     if ($is_dev) {
       $engine = $this->getSearchEngine();
       $nux_uri = $engine->getQueryBaseURI();
       $nux_uri = id(new PhutilURI($nux_uri))
         ->setQueryParam('nux', true);
 
       $actions[] = id(new PhabricatorActionView())
         ->setIcon('fa-user-plus')
         ->setName(pht('DEV: New User State'))
         ->setHref($nux_uri);
     }
 
     if ($is_dev) {
       $overheated_uri = $this->getRequest()->getRequestURI()
         ->setQueryParam('overheated', true);
 
       $actions[] = id(new PhabricatorActionView())
         ->setIcon('fa-fire')
         ->setName(pht('DEV: Overheated State'))
         ->setHref($overheated_uri);
     }
 
     return $actions;
   }
 
   private function canExport() {
     $engine = $this->getSearchEngine();
     if (!$engine->canExport()) {
       return false;
     }
 
     // Don't allow logged-out users to perform exports. There's no technical
     // or policy reason they can't, but we don't normally give them access
     // to write files or jobs. For now, just err on the side of caution.
 
     $viewer = $this->getViewer();
     if (!$viewer->getPHID()) {
       return false;
     }
 
     return true;
   }
 
   private function readExportFormatPreference() {
     $viewer = $this->getViewer();
     $export_key = PhabricatorPolicyFavoritesSetting::SETTINGKEY;
     return $viewer->getUserSetting($export_key);
   }
 
   private function writeExportFormatPreference($value) {
     $viewer = $this->getViewer();
     $request = $this->getRequest();
 
     if (!$viewer->isLoggedIn()) {
       return;
     }
 
     $export_key = PhabricatorPolicyFavoritesSetting::SETTINGKEY;
     $preferences = PhabricatorUserPreferences::loadUserPreferences($viewer);
 
     $editor = id(new PhabricatorUserPreferencesEditor())
       ->setActor($viewer)
       ->setContentSourceFromRequest($request)
       ->setContinueOnNoEffect(true)
       ->setContinueOnMissingFields(true);
 
     $xactions = array();
     $xactions[] = $preferences->newTransaction($export_key, $value);
     $editor->applyTransactions($preferences, $xactions);
   }
 
 }
diff --git a/src/infrastructure/export/format/PhabricatorExcelExportFormat.php b/src/infrastructure/export/format/PhabricatorExcelExportFormat.php
index 633d98fa53..2b0c787884 100644
--- a/src/infrastructure/export/format/PhabricatorExcelExportFormat.php
+++ b/src/infrastructure/export/format/PhabricatorExcelExportFormat.php
@@ -1,145 +1,168 @@
 <?php
 
 final class PhabricatorExcelExportFormat
   extends PhabricatorExportFormat {
 
   const EXPORTKEY = 'excel';
 
   private $workbook;
   private $sheet;
   private $rowCursor;
 
   public function getExportFormatName() {
     return pht('Excel (.xlsx)');
   }
 
   public function isExportFormatEnabled() {
-    return true;
+    // TODO: PHPExcel has a dependency on the PHP zip extension. We should test
+    // for that here, since it fatals if we don't have the ZipArchive class.
+    return @include_once 'PHPExcel.php';
+  }
+
+  public function getInstallInstructions() {
+    return pht(<<<EOHELP
+Data can not be exported to Excel because the PHPExcel library is not
+installed. This software component is required for Phabricator to create
+Excel files.
+
+You can install PHPExcel from GitHub:
+
+> https://github.com/PHPOffice/PHPExcel
+
+Briefly:
+
+  - Clone that repository somewhere on the sever
+    (like `/path/to/example/PHPExcel`).
+  - Update your PHP `%s` setting (in `php.ini`) to include the PHPExcel
+    `Classes` directory (like `/path/to/example/PHPExcel/Classes`).
+EOHELP
+      ,
+      'include_path');
   }
 
   public function getFileExtension() {
     return 'xlsx';
   }
 
   public function getMIMEContentType() {
     return 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet';
   }
 
   /**
    * @phutil-external-symbol class PHPExcel_Cell_DataType
    */
   public function addHeaders(array $fields) {
     $sheet = $this->getSheet();
 
     $header_format = array(
       'font'  => array(
         'bold' => true,
       ),
     );
 
     $row = 1;
     $col = 0;
     foreach ($fields as $field) {
       $cell_value = $field->getLabel();
 
       $cell_name = $this->getCellName($col, $row);
 
       $cell = $sheet->setCellValue(
         $cell_name,
         $cell_value,
         $return_cell = true);
 
       $sheet->getStyle($cell_name)->applyFromArray($header_format);
       $cell->setDataType(PHPExcel_Cell_DataType::TYPE_STRING);
 
       $width = $field->getCharacterWidth();
       if ($width !== null) {
         $col_name = $this->getCellName($col);
         $sheet->getColumnDimension($col_name)
           ->setWidth($width);
       }
 
       $col++;
     }
   }
 
   public function addObject($object, array $fields, array $map) {
     $sheet = $this->getSheet();
 
     $col = 0;
     foreach ($fields as $key => $field) {
       $cell_value = $map[$key];
       $cell_value = $field->getPHPExcelValue($cell_value);
 
       $cell_name = $this->getCellName($col, $this->rowCursor);
 
       $cell = $sheet->setCellValue(
         $cell_name,
         $cell_value,
         $return_cell = true);
 
       $style = $sheet->getStyle($cell_name);
       $field->formatPHPExcelCell($cell, $style);
 
       $col++;
     }
 
     $this->rowCursor++;
   }
 
   /**
    * @phutil-external-symbol class PHPExcel_IOFactory
    */
   public function newFileData() {
     $workbook = $this->getWorkbook();
     $writer = PHPExcel_IOFactory::createWriter($workbook, 'Excel2007');
 
     ob_start();
     $writer->save('php://output');
     $data = ob_get_clean();
 
     return $data;
   }
 
   private function getWorkbook() {
     if (!$this->workbook) {
       $this->workbook = $this->newWorkbook();
     }
     return $this->workbook;
   }
 
   /**
    * @phutil-external-symbol class PHPExcel
    */
   private function newWorkbook() {
     include_once 'PHPExcel.php';
     return new PHPExcel();
   }
 
   private function getSheet() {
     if (!$this->sheet) {
       $workbook = $this->getWorkbook();
 
       $sheet = $workbook->setActiveSheetIndex(0);
       $sheet->setTitle($this->getTitle());
 
       $this->sheet = $sheet;
 
       // The row cursor starts on the second row, after the header row.
       $this->rowCursor = 2;
     }
 
     return $this->sheet;
   }
 
   private function getCellName($col, $row = null) {
     $col_name = chr(ord('A') + $col);
 
     if ($row === null) {
       return $col_name;
     }
 
     return $col_name.$row;
   }
 
 }
diff --git a/src/infrastructure/export/format/PhabricatorExportFormat.php b/src/infrastructure/export/format/PhabricatorExportFormat.php
index 7e174f5197..4566814b9d 100644
--- a/src/infrastructure/export/format/PhabricatorExportFormat.php
+++ b/src/infrastructure/export/format/PhabricatorExportFormat.php
@@ -1,65 +1,53 @@
 <?php
 
 abstract class PhabricatorExportFormat
   extends Phobject {
 
   private $viewer;
   private $title;
 
   final public function getExportFormatKey() {
     return $this->getPhobjectClassConstant('EXPORTKEY');
   }
 
   final public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   final public function getViewer() {
     return $this->viewer;
   }
 
   final public function setTitle($title) {
     $this->title = $title;
     return $this;
   }
 
   final public function getTitle() {
     return $this->title;
   }
 
   abstract public function getExportFormatName();
   abstract public function getMIMEContentType();
   abstract public function getFileExtension();
 
   public function addHeaders(array $fields) {
     return;
   }
 
   abstract public function addObject($object, array $fields, array $map);
   abstract public function newFileData();
 
   public function isExportFormatEnabled() {
     return true;
   }
 
   final public static function getAllExportFormats() {
     return id(new PhutilClassMapQuery())
       ->setAncestorClass(__CLASS__)
       ->setUniqueMethod('getExportFormatKey')
       ->execute();
   }
 
-  final public static function getAllEnabledExportFormats() {
-    $formats = self::getAllExportFormats();
-
-    foreach ($formats as $key => $format) {
-      if (!$format->isExportFormatEnabled()) {
-        unset($formats[$key]);
-      }
-    }
-
-    return $formats;
-  }
-
 }