I'm running Mathematica 12 on Windows 10 pro, 64bit Processor together with Postgresql and Dbeaver. A professor wrote a tool to safe in advance prepared mathematica notebooks into the postgres database. I had everything running, but when I rebooted the computer to make it run smooth again and tried to reinstall everything, it did not work anymore.

I reinstalled Mathematica on the latest version, Postgresql, Dbeaver. I renamed the folders, double checked if there is no appendix or mistake. And also tried other libraries and books. It somehow seems to be a problem by Mathematica, but I really don't know what to do.
Does anyone have an idea or did anyone ever experience a similar problem?
Best Philip