Unknownreported this bug
Summary
An error log occurs on server startup, and mobs such as Wither are spawned.
Steps to reproduce
On server startup
Current behavior
Wither and other mobs spawn every time the server starts.
Server log file
+) Even with mob spawning disabled via game rules, mobs are still generated due to the MythicMobs plugin when the server starts.
The image below shows the list of mobs killed using the /killall all command.
/gamerule doMobSpawning false
[Legacy attachment omitted]