multiplayer issues with 0.88.8

every time I host or try to join a multiplayer game, an error messages pops up saying check mod sum, you may be running of a different version than the host, tried hosting with a friend who also has 0.88.8 and same issue, even when I uploaded the file to mega and had him download it, and vice versa.

Hey Everyone!
I am also facing same issue please help me to get ridge of this.