Crash report: https://pastebin.com/Ze9RvQwq

I think this is a mixin incompatibility. Bewitchment is using mixin 0.8.

Ok never mind, Level Up was using an outdated mixin version, so it crashed everything. Updated it and everything is ok.

I dont get this crash... My built-it mixin is 0.8.1 and requires 0.8.0. Maybe there is a mod in your pack which has lower mixin version or other requirements? Please post a full log (latest.log)

https://pastebin.com/uGxJ0xUi