Thread:Project:Support desk/thumbnails not working and group permissions in LocalSettings don't have any effect after migration from MAMP to Ubuntu 14.04 LTS

Hi,

I recently migrated my mediawiki-installation from a local MAMP version to a Ubuntu Server 14.04 LTS. After some minor problems, almost everything works fine. I can view and edit pages, see all the content, upload files, etc. Only problem I'm encountering so far is the missing thumbnails, which cannot be created because they cannot be created in that folder.. I found some old threads from 2012 but changing the concerning lines in LocalSettings.php or GlobalSettings.php didn't help,

I also tried setting up Userpermissions in LocalSettings.php (at the bottom), but they don't have any effect on my wiki. E.g *** $wgGroupPermissions['*']['edit'] = false; *** should deny making changes for anybody, but even without logging in, I can easily alter pages.

Now I think that somehow my migrations screwed up permissions on both, the temp directory for thumbnails (existing thumbnails from before the migration still work!) and/or my LocalSettings.php. In both cases, 'www-data' has read-write permissions and after hours of trying I just don't know where to go on..

Thanks a lot in advance

mediawiki version is 1.23.1, php 5.5.9-1ubuntu4.3, mysql 5.5.38-0ubuntu0.14.04.1