What happened?

The game would just suddenly crash.

It didn't really matter what I was doing, or even how long I was playing, it could take up to like 10 minutes or as little as a few seconds before the crash. I could also run with my horse in a dense forest or just standing in my base reading JEI. Nothing I did would cause the crash, the game would just sometimes freeze and then crash.

At first I had no reason to believe it was this mod causing the trouble since the crashlog didn't mention it in any relevant way as far as I could understand it, but after hours of checking and deleting mods and then getting rid of most mods and adding them a few at a time, it's when I found this mod was causing the problems, I then tested three times with the mod, and three without, and every single time, it would only crash when I had Rough Mobs Revamped.

Minecraft Version

1.16.5 (Default)

Forge Version

1.16.5-forge-36.2.20

Mod (RMR) Version

1.16.5-0.0.3

Crash Log

https://pastebin.com/bzzdGNhs

Seems to be as the entity is being added to the world, itself or its passengers get changed as the entity is being added. Mod is not playable in survival until this issue is resolved.