Why can't i suddenly not edit skripts?

suddenly i cant edit skrips ( background color is grey, exclamation ding ) under Win64?

I can open skripts and download it to Arduinos but can not edit them or save them under a normaul user account. Run as administrator doesn'n help.

I installed the IDE again with setup and from zip but same result.

If i change to administrator account it works.

please help
thank's

I learned that:
"That is a /terrible/ way to tell you that you have selected an external editor."