Pls help attempted to load class for invalid dist Dedicated Server

Pls help my friends and I wanted to try making our own mod pack, but we keep getting kicked. We receive a message saying Illegal packet received after entering the server. I checked the mod lists and versions and they all match up. The only error in the logs is something about loading a class

here's the server logs: https://mclo.gs/NCN6kFW

Omg I scrolled down to see so many errors I'll test each mod one by one to see what's going on. (I thought it was just the DistxForm error)