Version information

ItemSwapper 0.6.3

Other relevant installed mods

Quilt 0.26.0 | Quilt Fabric API 9.0.0 | ModMenu 9.2.0-beta2 | Sodium 0.5.8, with lithium and Indium | Carpet, tweakeroo ect

Expected Behavior

Joining a singleplayer world

Actual Behavior

Upon loading the world, an error appears with "Connection Lost, Server sent an invalid packet", with the only option to get back to the server list even if I was in singleplayer.
edit: my previous 1.20.4 modlist was using Quilt with Fabric API and ItemSwapper 0.5.5, but same thing happens if I load Quilted Fabric API.

Reproduction Steps

Load mod with Quilt (seems to be the issue)
Play your singleplayer world

Render engine

• Vanilla
• Sodium(optionally with Iris)
• Optifine
• VulkanMod
• Canvas
• Other

Additional information

No response

I won't look into quilt issues. I know there are issues with the networking right now, but it certainly works on Fabric singleplayer.