Indexhibit Support

After installing, upgrading doublechecking server i still have following problem: I can not change ANY setting. Not even the time. It wont save. In formats and sections nothing is reacting.
I researched everything, I have mySQL5.7, PHP 5.6.
I just cant find any solution. Does this Proble sound familiar to anybody? If I try to create indexlink or exhibit this appears:

Warning: Invalid argument supplied for foreach() in /homepages/u53866/ndxzstudio/module/exhibits/files.php on line 25

By the way: same settings with my older website, everything works just fine. The code in ndxzstudio/module/exhibits/files.php is also the same. I compared it in TextEditor.

Right now Im creating a new db with MySQL 5.5 instead 5.7. Hope it will help.