diff --git a/src/applications/transactions/editfield/PhabricatorEditField.php b/src/applications/transactions/editfield/PhabricatorEditField.php
--- a/src/applications/transactions/editfield/PhabricatorEditField.php
+++ b/src/applications/transactions/editfield/PhabricatorEditField.php
@@ -320,7 +320,13 @@
   }
 
   protected function getValueExistsInSubmit(AphrontRequest $request, $key) {
-    return $this->getHTTPParameterType()->getExists($request, $key);
+    $type = $this->getHTTPParameterType();
+
+    if ($type) {
+      return $type->getExists($request, $key);
+    }
+
+    return false;
   }
 
   protected function getValueFromSubmit(AphrontRequest $request, $key) {
@@ -328,7 +334,13 @@
   }
 
   protected function getDefaultValue() {
-    return $this->getHTTPParameterType()->getDefaultValue();
+    $type = $this->getHTTPParameterType();
+
+    if ($type) {
+      return $type->getDefaultValue();
+    }
+
+    return null;
   }
 
   final public function getHTTPParameterType() {
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -1888,7 +1888,7 @@
     }
 
     foreach ($no_effect as $key => $xaction) {
-      if ($xaction->getComment()) {
+      if ($xaction->hasComment()) {
         $xaction->setTransactionType($type_comment);
         $xaction->setOldValue(null);
         $xaction->setNewValue(null);