The Error screens says something along the line of "An unexpected Error occurred. We are sorry for the inconvenience. Exit Code 1."

Sadly, I didn't have a proper crash report. Just showed the error and that's it.
But I updated my server to 1.20.1 on Saturday and the error is not occurring anymore.
But still, thanks for your time. :)

Here is the mod list btw.

Could you please send the entire crash report?