Bohemia Interactive's latest Arma2 update has now broken the linux servers, But all is not lost. You can still play the Dimrod servers by using legacy mode.
In your library, right click on Arma 2 OA, properties, betas, drop down window, legacy, then close the window
Blastcore Visuals (requires CBA) has been messed up for some time for arma 2 multi-player this is a download of a working version for our servers using the play with six keys
@blastcore_visuals.r1.2.zip