Thread:Project:Support desk/Error creating thumbnail/reply (4)

If there's no debug log, it may be that the server doesn't have permissions to write on the folder where the debug log would be created. Check those permissions, or point the debug log somewhere in the /tmp directory.

You may be on a shared host, in this situation you normally don't have access to all the filesystem, and instead you're chrooted on your own folder. If imagemagick is installed and the convert program accessible from your account, it may be on the $PATH, so maybe specifying just "convert" as the command may work.