Information

Minecraft version: 1.15.2
Forge version: 31.2.30
Environment: Multiplayer

Mod name: Skeleton Horse Spawn
Mod version: 1.3

Description

java.util.ConcurrentModificationException: null

Crash report

crash-2020-08-31_15.30.06-server.txt

Are you able to reproduce this crash?

Yeah, it happens when dedicated server just started and someone (in nearest 10 seconds) tries to enter the server.

This happens because you are using iteration mechanism in loop through entities.
Instead try to create some local buffer list for iteration through entities (so changes in original list won't cause such issue)

Thanks for letting me know and using the mod! I've fixed the issue in the latest version. In the end decided to use "CopyOnWriteArrayList", instead of making a manual copy. The other Spawn mods have been altered as well.

https://www.curseforge.com/minecraft/mc-mods/skeleton-horse-spawn

Thank you 😄