I think the Differential (which is disabled in my install) is used anyway to parse an SVN commit and that raises an exception.
[2014-04-22 12:51:59] EXCEPTION: (PhutilProxyException) Error while executing task ID 61011 from queue. {>} (ConduitException) Method 'ConduitAPI_differential_parsecommitmessage_Method' belongs to application 'Differential', which is not installed. at [/home/sites/phabricator/web/phabricator/src/applications/conduit/call/ConduitCall.php:204] #0 ConduitCall::buildMethodHandler(differential.parsecommitmessage) called at [/home/sites/phabricator/web/phabricator/src/applications/conduit/call/ConduitCall.php:21] #1 ConduitCall::__construct(differential.parsecommitmessage, Array of size 2 starting with: { corpus => Mobile - Event Edit - Ticket Price Field Extends Beyond Window }) called at [/home/sites/phabricator/web/phabricator/src/applications/diffusion/query/lowlevel/DiffusionLowLevelCommitFieldsQuery.php:23] #2 DiffusionLowLevelCommitFieldsQuery::executeQuery() called at [/home/sites/phabricator/web/phabricator/src/applications/diffusion/query/lowlevel/DiffusionLowLevelQuery.php:23] #3 DiffusionLowLevelQuery::execute() called at [/home/sites/phabricator/web/phabricator/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php:49] #4 PhabricatorRepositoryCommitMessageParserWorker::updateCommitData(Object DiffusionCommitRef) called at [/home/sites/phabricator/web/phabricator/src/applications/repository/worker/commitmessageparser/PhabricatorRepositorySvnCommitMessageParserWorker.php:15] #5 PhabricatorRepositorySvnCommitMessageParserWorker::parseCommit(Object PhabricatorRepository, Object PhabricatorRepositoryCommit) called at [/home/sites/phabricator/web/phabricator/src/applications/repository/worker/PhabricatorRepositoryCommitParserWorker.php:44] #6 PhabricatorRepositoryCommitParserWorker::doWork() called at [/home/sites/phabricator/web/phabricator/src/infrastructure/daemon/workers/PhabricatorWorker.php:85] #7 PhabricatorWorker::executeTask() called at [/home/sites/phabricator/web/phabricator/src/infrastructure/daemon/workers/storage/PhabricatorWorkerActiveTask.php:123] #8 PhabricatorWorkerActiveTask::executeTask() called at [/home/sites/phabricator/web/phabricator/src/infrastructure/daemon/workers/PhabricatorTaskmasterDaemon.php:19] #9 PhabricatorTaskmasterDaemon::run() called at [/home/sites/phabricator/web/libphutil/src/daemon/PhutilDaemon.php:85] #10 PhutilDaemon::execute() called at [/home/sites/phabricator/web/libphutil/scripts/daemon/exec/exec_daemon.php:112]