Body part regrowth causes error

[vladislemon]

Description:
Error pop up in log when body part completes regrowing. Didn't notice any effect on gameplay yet.

To Reproduce:

1. Choose pawn with ability to regrowth body parts.
2. Destroy any non vital body part.
3. Wait this part to regrowth.

Expected Behaviour
No error in log.

HugsLib Log:
https://gist.github.com/HugsLibRecordKeeper/ec1a9286875a813684467330d82189e4

Additional context
RimWorld 1.5
I'm using Archinite genotype from Arhotech Genetics.