I can't seem to solve this problem. It happened when i was trying to join a multiplayer server through the curseforge download of All of Fabric 3.

Closing this due to lack of activity, feel free to reopen if this still occurs

Make sure you're using the same pack version that the server is using.

This seems to be a pack / user issue anyways, but make sure your pack versions are in sync like AK9 said and try to connect again, please