Thread:Project:Support desk/Fatal Error with SpecialListfiles.php/reply

OK, answering myself:

I knew that I had problems with an ogv-Video a few days ago. I deleted that File:Video.ogv an now the Special:Listfiles works again.

I tried php checkImages.php before, and got the result that 0 images are ok and that 298 images are missing. But my wiki runs fine and the Special:Listfiles page works ok, too.

What's is wrong here?