I am currently having an issue trying to get all the mods 5 to work. It previously functioned fine, until a few days ago when it started saying "incompatible fml modded server". I have reinstalled the modpack twice and the server modpack once. Still the same error. Tried to join multiple times and got the mismatched mod channel list error repeatedly.
I don't know whats causing this. As far as I can tell, forge and all of the mods are on the same version client and server side. I looked at some other similar threads but couldn't find one that worked. I want to state that this worked until I updated the server to modpack version 1.11. I waited for it to update to see if it would fix itself and it did not.