Data Objects menu not expandable


I installed Pimcore new.
And now I’m not able to expand the menu for Data Objects:


There is just a thin grey line visible.
Menu’s in documents and Assets are not affected.

What can I do?

did you already create object classes? …


Dear Christian

Yes you’re right!
I’t works fine now.

Many thanks


I ran into this problem, but I did have classes. It turned out to be a db issue - I had a class listed in the classes table which didn’t have any corresponding files in the code. Deleted that table entry and it fixed the problem.

The error that got me there was in prod.log:
pimcore.ERROR: Exception: Class definition with name myClass2 or ID 2 does not exist