Hey guys, just a quick fix for people that want to get on the server now, takes only 2 mins to fix (other than update).
Firstly go to steam, and right click arma 3 and go to properties.
Second go the "Betas" Tab, and paste in this code "Arma3Legacy156".
Then select legacy - Legacy Build 1.56.
Let it update and you're done!
When the server gets updated just put the legacy mode back to normal.
http://clip2net.com/s/3xe9vBC
Hope this helps!