Hit this rather recently, haven't debugged anything at all. But it happens when I open the Auth config for LDAP. I suspect it's an easy fix, hence I haven't tried debugging. Otherwise I'd be glad to provide more information if you need/want!
2405#0: *5541 FastCGI sent in stderr: "PHP message: [2014-01-08 13:14:12] ERROR 2: strlen() expects parameter 1 to be string, array given at [/usr/lib/phabricator/src/applications/auth/provider/PhabricatorAuthProviderLDAP.php:364]
PHP message: #0 strlen(Array of size 2 starting with: { 0 => givenname }) called at [/usr/lib/phabricator/src/applications/auth/provider/PhabricatorAuthProviderLDAP.php:364]
PHP message: #1 PhabricatorAuthProviderLDAP::renderConfigPropertyTransactionTitle(Object PhabricatorAuthProviderConfigTransaction) called at [/usr/lib/phabricator/src/applications/auth/storage/PhabricatorAuthProviderConfigTransaction.php:127]
PHP message: #2 PhabricatorAuthProviderConfigTransaction::getTitle() called at [/usr/lib/phabricator/src/applications/transactions/view/PhabricatorApplicationTransactionView.php:304]
PHP message: #3 PhabricatorApplicationTransactionView::renderEvent(Object PhabricatorAuthProviderConfigTransaction, Array of size 7 starting with: { 0 => Object PhabricatorAuthProviderConfigTransaction }, 38) called at [/usr/lib/phabricator/src/applications/transactions/view/PhabricatorApplicationTransactionView.php:75]
PHP message: #4 PhabricatorApplicationTransactionView::buildEvents() called at [/usr/lib/phabricator/src/applications/transactions/view/PhabricatorApplicationTransactionView.php:95]
PHP message: #5 PhabricatorApplicationTransactionView::render() called at [/usr/lib/phabricator/src/view/AphrontView.php:159]
PHP message: #6 AphrontView::producePhutilSafeHTML() called at [/usr/lib/libphutil/src/markup/render.php:85]
PHP message: #7 phutil_escape_html(Object PhabricatorApplicationTransactionView) called at [/usr/lib/libphutil/src/markup/render.php:107]
PHP message: #8 phutil_escape_html(Array of size 3 starting with: { 0 => Object PhabricatorCrumbsView }) called at [/usr/lib/libphutil/src/markup/render.php:107]
PHP message: #9 phutil_escape_html(Array { 0 => Array of size 3 starting with: { 0 => Object PhabricatorCrumbsView } })