I was trying to setup a new Plex Server and move the movies and shows using the guide from support.plex.tv.
The problem is, that I’m not able to log on the initial setup. The error message is always “Internal Server Error. Somthing went wrong on our end”.

Things I tried without a change:
I installed the Plex Server on an other Device running Windows, but the error stays the same.
I also changed my DNS to 1.1.1.1 to be sure that my PiHole is not the issue.
I used firefox on the Linux device and vivaldi on the other Windows 10 device.
I hope someone can help me with this issue.
Regards
toru
