Is it a mod compatibility issue?

Yes

If it's a mod compatibility issue, please provide the link(s) to the incompatible mod(s)

https://modrinth.com/mod/iris

Minecraft version

1.20.4

Describe the issue

I decided to create an assembly for general use and would really like to add this mod to the assembly. But since most players have weak PCs, it was necessary to add the Iris mod there. Having wanted to check the functionality of the assembly, it did not start. Fabric wrote that the Iris mod is not compatible with any version of Immersive portal. I contacted the Iris forum, they replied that you did not respond to the proposal for a joint solution to the problem. I decided to ask you for help. Can you fix this problem? I'm really looking forward to the result 🤝