Is it a mod compatibility issue?

No

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

No response

Minecraft version

Other (specify below)

Describe the issue

Made sure ALL mods are on MC version 1.20.2 and everything works, but when I add your mod, it then tells me to add it to the server files(even tho im running SP only) No idea whats going on.

Are you using bad packets mod? Bad packets mod could cause this issue. #1456

If not, to know whether it's a mod compatibility issue, backup your world and test it with only Fabric API and Immersive Portals mod.

Don't I need badpackets for it to run? And sure I can do that. Let me test that out and get back to you.

No, I mean that someone reported having similar issue when using Bad Packets mod. ImmPtl does not require bad packets.

Update: someone reported that similar issue also occurs with essential https://discord.com/channels/662271867431682058/671895714527182920/1162676318228447374

Are you using essential?

ImmPtl uses Fabric API's functionality to check whether the client has ImmPtl. Seems that essential mod or other mod breaks this. If you get this issue with essential, you can report this issue to essential.

In 4.0.2 https://github.com/iPortalTeam/ImmersivePortalsMod/releases/tag/v4.0.2-mc1.20.2 you can disable the check from the server side by setting the server side's serverRejectClientWithoutImmPtl to false in the config file config/immersive_portals.json .