Hey,
The version Overlord-1.11.2-2.3.1 causes an IndexOutOfBounds Exception and shuts down the internal server. I have changed back to Overlord-1.11.2-2.2.3 and the error disappeared.

Log with Crash Report is attached
would be great if you could look into it with a possible fix

Thanks in advance
and keep up the great work :)

mc_crash_report.txt

Thanks for reporting it! I now see the issue, and will release a fix asap.

Fixed in 2.3.2