I am in the process of testing MCMT with a variety of mods to see what works and what does not. But I noticed that with one mod in particular I tend to get log spammed nullpointerexeptions, I know which mod is the culprit and I know what specific thing about the mod causes it however it does not always happen and when it does the server never crashes. If I unload and reload the problematic chunk the error spam is gone. I have seen arrayoutofbounds exceptions with roadrunner, a lithium port to 1.16.5 for forge too. But there aren't any errors that break the game.

The only errors that actually did crash the game was when I was pregenerating the overworld while being in it with chunk pregenerator. I think this is most likely due to the mod doing its thing in a way that conflicts with MCMT. However pregenerating the dimension when it is not loaded works.

So I ask, is it normal for the game to keep running after these errors that are not crashing the server? Are they being corrected?

One more thing. In vanilla, wolves seem to have issues with concurrency and wandering traders throw an error once in the game but the game also keeps running and nothing seems out of the ordinary. How can I know if something is "working" especially if the server is not crashing?

I have decided to discontinue testing 1.16.5. Regardless of whether this mod is present or not, performance on this version of Minecraft is so bad it is not worth trying for a functional modpack or vanilla gameplay at all. Please disregard this issue.