According to your testing, does the issue occur with ONLY Immersive Portals mod installed?

Yes

Forge Version

43.3.0

ImmersivePortals Version

2.3.5-mc1.19.2-forge

Latest Log

https://gist.github.com/Explode007/c8d6b0e9078952bcee1a94b420c74346

Crash Report (if applicable)

https://gist.github.com/Explode007/407e2f2d9de181148ae8e1d9aac16fbc

Steps to Reproduce

1. Install Immersive Portals & alexsmobs
2. Make a world
3. First time loading crashes
4. Second time and subsequent loads don't crash
5. Why.

What You Expected

Load world with no problems on first try

What Happened Instead

Game crashes with Registry is already frozen error message

Additional Details

Only exclusive to forge version, seems to be that alexs mobs is the problem given when enabled, the problem was occurring and when disabled, stopped occurring.

Sorry if this is a duplicate of #123 and/or #146, I thought I would list this since it's pretty different in my eyes.

Please Read and Confirm The Following

• I have confirmed this bug can be replicated without the use of Optifine.
• I have confirmed the details provided in this report are concise as possible and does not contained vague information (ie. Versions are properly recorded, answers to questions are clear).
• I have confirmed this does not happen on the fabric version (If it does please report to here instead).
• I have confirmed I'm not using a hybrid server (Magma, Cauldron) or a different (non official) Forge Server release.
• I have confirmed this issue is unique and has not been reported already.