Multiplayer problems

[Mictheslik]

when I try to join a multiplayer server it says that i dont have the same game version as the server (or a protocol mismatch)

I have downloaded v3.1a but it still says the same. Please help.

[Mathias]

There are a lot of blokes who still fly the unpatched 3.0 version of the game.
Also if the host uses third party planes or mods that you don't have you'll get missmatches