[ Please replace text in [] with the answer from the above question! ]

Do you use Java 8?
Yes

What version of Minecraft do you use?
1.12.2

What version of MinecraftForge do you use?
14.23.2.26.40

What version of SanLib do you use?
1.4.2

What version of Clay Soldiers do you use?
Alpha 9,1

What is the issue / bug you have encountered? Give us a short description.
This time when I log in into the server, it crashes the server every time.
EDIT: I have not been able to come on since this started happening.

How can it be reproduced?
Not sure
crash-2018-02-04_08.53.22-server.txt

Please post your log file (either in /logs/fml-client-latest.log or /logs/latest.log) on https://gist.github.com and provide the link:
https://gist.github.com/BobRossss/03833333a56323932d31773a9eb9c91a

Not a mod issue, seems you don't have the right file permissions on your session.lock file of your server world. For more info, look here: https://gaming.stackexchange.com/questions/184226/how-do-i-fix-the-failed-to-check-session-lock-for-world-error

Oh, ok thanks! Sorry for wasting your time.