DropOptions(ChatMessage) not working

Summary

When killing a mob that has ChatMessage in drop options it throws err.

Steps to reproduce

Use MythicMobs-5.10.0-SNAPSHOT 5496 on Purpur v1.21.8-2489-HEAD@4fd4df0. Create new vanilla mob modification: https://pastebin.com/932xmSbQ Summon that mob and kill it.

Current behavior

We get err: https://pastebin.com/MhxDRLkF

Intended correct behavior

Message sent into chat.

Server log file

https://pastebin.com/YNrZujrX

Debug log snippet

https://pastebin.com/wDcvHW8D