Thread:Project:Support desk/Thumbnails are not working, MW 1.21.1

My thumbnails for uploaded images aren't working. Some details: -> with $wgUploadDirectory = "$IP/images"; and $wgUploadPath = "$IP/images"; there are no changes
 * exec is activated, but no passthru (not possible on my webspace) and so I get an error when using ImageMagick.
 * without ImageMagick the thumbnails aren't displayed/generated
 * I tried to define some paths in the LocalSettings.php -> with #$wgTmpDirectory = "$IP/images/temp"; the picture list is empty
 * the folder rights for /images, /images/thumb and /images/temp are set to 755
 * I'm using BlueSpice

Any ideas?