I keep crashing while fighting the mutated aechor plant. I'm using the resistor shield and ray gun from alex's caves mod to fight the plant. This didn't happen the first time I was fighting the aechor plant even with the same weapons. There is no crash log I can post besides this screenshot. I hope this helps.

Now I was just using an iron axe and it crashed. It crashed the moment I got the green heart effect

It also crashes with that error without that affect. I'm not sure what is causing it. Any time the green heart effect came up it crashed. Maybe I'm crashing before I see it sometimes.

I can barely even enter the world now. Most of the time it crashes before loading in but rarely I get a few seconds in the game.

I am also playing on a private server if that has any impact on the bug,

After a quick test this bug does NOT occur in singleplayer even when using the same gear

That is a bit odd, I unfortunately don't have a proper way to test multiplayer bugs but I'll look into it once I have time

New error thrown. I saw this pop up once before but I didn't capture it at the time. Maybe this will help?

Hi after trying to find reason for my server crash I can confirm that I'm having the same issue when fighting Mutated Aechor Plant. The game crash when the plant fire the box green thingy

Yeah this still seems to be an issue as I am experiencing the same thing

I found out why it happens! It's the projectiles it shoots out and then the effect it gives! When the effect wears off the first time, you are stuck at that place, continously getting kicked or crashing until you either defeat the boss or teleport away!

Looking into this, no guarantees I'll figure it out, but:
f_132289_ is the particle field in ClientboundLevelParticlesPacket, where it's crashing in the write method due to attempting to get the type of a null particle.