[Typo3] Problems with showpic.php

[Andreas Balzer]

Hi!
I have a big problem with showpic.php. If i click on a thumb image on my 
typo3 FE, just a white window opens. There are no contents. If i download 
showpic.php to my computer, it's just empty and 0 bytes big. Well, someone 
said me, that this is just a symbolic link to the real file. But where is it 
situated? Please help me, i really do not know, what i could do.

Andreas