Cant join MP - files not signed

[Stogie 10]

I cant join any multiplayer server as several of my files say they are unsigned (I just bought the game on steam).

One example file: C\program files\steam\steamapps\arma 3\addons\anims_f.pbo

What is wrong, how can this game not have "signed" files when all i have done is download it from steam?

Please help, if i cant find an answer i will have to return the game.

Thanks

[brucehamill 1]

No doubt the srevers you are trying to connect to are running mods, if you dont have the correct keys and correct mods you get get the unsigned message i believe, check when you select a server that there are no mods running on it.