Thread:Project:Support desk/Special:Upload Exception from line 244 UpdateStash.php

I am now getting errors when trying to upload files to MediaWiki 1.22.3.

[307d6bc7] /wiki/Special:Upload Exception from line 244 of /wiki/includes/upload/UploadStash.php: Error storing file in '/tmp/phpMHAun4': "mwstore://local-backend/local-temp/f/f4" is not a valid storage path. Backtrace:
 * 1) 0 /wiki/includes/upload/UploadBase.php(844): UploadStash->stashFile(string, string)
 * 2) 1 /wiki/includes/upload/UploadBase.php(857): UploadBase->stashFile
 * 3) 2 /wiki/includes/upload/UploadBase.php(866): UploadBase->stashFileGetKey
 * 4) 3 /wiki/includes/specials/SpecialUpload.php(340): UploadBase->stashSession
 * 5) 4 /wiki/includes/specials/SpecialUpload.php(433): SpecialUpload->showUploadWarning(array)
 * 6) 5 /wiki/includes/specials/SpecialUpload.php(179): SpecialUpload->processUpload
 * 7) 6 /wiki/includes/SpecialPage.php(631): SpecialUpload->execute(NULL)
 * 8) 7 /wiki/includes/SpecialPageFactory.php(488): SpecialPage->run(NULL)
 * 9) 8 /wiki/includes/Wiki.php(298): SpecialPageFactory::executePath(Title, RequestContext)
 * 10) 9 /wiki/includes/Wiki.php(602): MediaWiki->performRequest
 * 11) 10 /wiki/includes/Wiki.php(467): MediaWiki->main
 * 12) 11 /wiki/index.php(49): MediaWiki->run
 * 13) 12 {main}

These were visible after I added the following to :

error_reporting( -1 ); ini_set( 'display_errors', 1 ); $wgShowExceptionDetails = true;

I don't even know where to start on this. Any help appreciated.