Technical Specs (please complete the following information):

• Craft to Exile Version; 2.10.6
• World Type: Multiplayer
• RAM Allocation: 10 Gb

Describe the bug
Often when playing (exploring) i get disconnected from my own server and i am not able to join back, because every time i attempt to do it I get disconnected with the following error:
"The game crashed whilst rendering entity in world Error: java.lang.NullPointerException: Rendering entity in world Exit Code: -1"
Even after restarting the server, the error persist.

To Reproduce
Steps to reproduce the behavior:

1. Start running in a random direction
2. Suddenly game crashes with the error shown above.
3. Try to reconnect every time.
4. Keep getting the same error.

Expected behavior
Not crashing while exploring.

Additional Information (screen shots, etc.)
I tried removing some mods, killing the player as soon as joining the server, moving for the split second after the world leaded on the client, restarted the server over and over, teleported the player far away.
Connection is stable from both server and client, Server has RAM allocation capabilities up to 64 GB, client to 32GB, no console log to be show in client crash logs, except for the error shown above. Server doesn't crash, only client.
I will attach the latest server log file.
latest.log

Finally managed to get a client crash after 10/15 attempts of joining failed.
latest.log
crash-2021-06-20_14.16.48-client.txt

if i read the crash log right its lycanitesmobs: zoataur that is your problem

With the older server crash we had minecraft:bat as the cause of the same error. Also seems like apotheosis is the one spawning the zoataur? I am non familiar with that mod, so i have no idea if it's the case. I can try and remove lycanites mod, but i doubt it isn't going to affect the whole pack/questline.
Should I try to edit the config for apotheosis to not spawn zoataurs?

check the apotheosis config and lycanitesmobs config

Both client and server has same CFG files from both the mods.
The only weird thing that i find (but i may be wrong) is this:
"name": "zoataur",
"enabled": false,
"spawning": {
"enabled": false,
"spawners": [
"sky"
]

Shouldn't this mean that it isn't supposed to spawn, except from spawners?

So, if this is right, if i remove "sky" everything should be fine?

Also, if it can be helpful to find and fix the effective problem, issues appeared since we created a brand new server of CtE[Dissonance] 2.10.6. First time happened, we wiped the entire server just to test for a wrong installation.
Brand new server, brand new world seed, different biome, same type of crash with entity "minecraft:bat".
This time, third server and third world, different biome, and also a friend of mine got close to the "area" of the issue and also crashed with the same error. Server.zip file was downloaded from official Curse website, on the page of Craft to Exile

Created an account just to give this a +1, I had to grab a backup of my server to play again. Accidentally wandered back into the area and boom broke again

I went into server config > lycanitesmobs > spawners > sky.json and changed enabled to true
server config > lycanitesmobs > creatures> zoataur.json and changed enabled to true
then the same thing for client side and mine works now

I encountered this crash just a bit ago as well and it was due to the the Zoataur being set to spawn from a random spawner underground.

Update, my game crashed again due to this problem

I temporarily (sorry for my english) solved the issues by removing the Zoataur json file inside ./config/lycanitesmob/creatures and turning to false the autoLoadDefault inside the 3 main cfg files. Seems to be working now but I assume there are better ways to fix the issue.
10+ hours of 2 people running around aimlessly and in previously bugged spots, still no crushes.

I encountered this crash just a bit ago as well and it was due to the the Zoataur being set to spawn from a random spawner underground.

I am pretty sure that is what is causing the issues to me, too. Even tho from the config file it seems he should only spawn in "sky"

Lycanites is weird. Because you have already got a spawner that generates Zoataur, you will need to either enable him and enable his spawning (no need to touch Sky spawner json), or go into the region nbt and delete taht spawner. Sorry I didn't realize something like this would have happened. I really dislike Lycanites, it just has a bunch of problems.

Also to shine some light on why this is happening now:
Zoataurs were accidentally enabled in a patch a while ago, and so I disabled them recently. However, spawners already set to spawn zoataurs would cause the error because they weren't able to be found (since they were disabled). I have no intention of reenabling them as this should resolve itself slowly over time as players move on from the older versions. Just follow the above and you should be able to fix it.

Not sure about taht bat though