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

Yes

Forge Version

40.1.18

ImmersivePortals Version

1.4.11-mc1.18.2

Latest Log

https://gist.github.com/M3hdiPG/a58de6650e18ff844064c44f37dbc37c

Crash Report (if applicable)

https://gist.github.com/M3hdiPG/b34cdbeab7da3bdba40b79c4c379f62b

Steps to Reproduce

The error happens when a player joins the server

What You Expected

I expected to join the server and that everything goes well

What Happened Instead

the server crashes as soon as i join the serer

Additional Details

No response

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 this issue is unique and has not been reported already.

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

Shows log with hundreds of other mods...

Anyway, their is an issue not caused by immptl not allowing you to join: You're simply reaching the maximum size of the connection sync package. This is due to having so many mods. It's a vanilla limitation, nothing I can deal with. You can try a mod increasing that limit, though I wont guaranty it to work with immptl.

About the crash: No support with that, I'm having no time to support Hybrids (Magma). If you can reproduce this on a Forge Server feel free to reopen this issue.