Alright, did some google searching and think I have found the cause, or at least potential cause. Does the server you are trying to connect to use cauldron or something similar?
The error is the result of high latency and the server not getting all of the proper info from minecraft servers as you try to log in.
Way to verify, can you play any map using your preferred modpack in SSP?
The error is the result of high latency and the server not getting all of the proper info from minecraft servers as you try to log in.
Way to verify, can you play any map using your preferred modpack in SSP?