[TYPO3] BE Filelist empty white page instead of files

[Costa Papadopoulo]

Hi all,

just upgraded my TYPO3 Version 4.1.2 to 4.1.6.

Everythiung is working fine. But when I click on "Filelist" in  Backend, it 
does not give me the filelisting, but only a white page.

I did compare in Install tool, also update wizard.
All rights are correct on the fileadmin -R files and folder.

What could be the prob?
What did I miss during upgrade?

Regards
costa