Thread:Project:Support desk/Image upload not working after upgrade/reply (2)

Check your temporary directory (which ever one is used by php. It should probably be specified in php.ini) is writable by the webserver. Also double check all the upload related settings in php.ini to make sure they are correct.

(If that's the issue, it may indicate a bug in mediawiki, as mediawiki should handle such situations more gracefully. Of course this is a guess, so it could be some whole other issue)