If there's an update, any update as far as I know, if you play multi-player every person connecting to the server needs to have the same version as the server running the game.

You need to reach out to the host of the server and have them update to the latest version.

Originally posted by speediepa24:

Has there been a lot of updates for the server side of game? Last few day when trying to join an IP it says failed to connect! and have to wait for the server to be updated.

in future if you are playing on 3rd party servers, contact them first.
there is little if anything people can do to help here.