When going into the Regeneration Tab and choosing Select Next Incarnation the game immidently crashes.

Steps to reproduce the behavior:

1. Use Regeneration-1.12.2-1.9.5 and Forge 1.12.2-14.23.5.2838
2. Click on Select Next Incarnation
3. See error

Crash Report:
crash-2019-09-09_15.14.26-client.txt

That's fairly odd, this shouldn't happen at all
I'll patch it tonight, thank for reporting!

Been a bit delayed in fixing this, I apologise for that. Looking into this as I type this