I upgraded mediawiki (from 1.14 to 1.24) with the following parameters:
PHP 5.4.29 (apache2handler)
MySQL 5.1.69-log
More software and extensions installed can be found at: http://www.imkerpedia.nl/wiki/index.php/Speciaal:Softwareversie
After upgrading (and the needed copying of the image-folder) some pictures (sizes) are shown, but others aren't. To me it's completely random why some pictures (with specific picturesizes) don't exist in images/thumb/././, and others do.
After rereading http://www.mediawiki.org/wiki/Manual:Upgrading I see I forgot 'chmod -R 755 images' and 'chgrp -R apache images'.
At the moment all (sub)folders in the image-folder are 755 or 777. The image-folder itself is 755. So, that that's okay, isn't it?
However, I don't know how to 'chgrp -R apache images' (if that's the problem).
I'm using FTP (Total Commander) to manage files.