This happens quite frequently to me, I find a server, say it shows 12 of 14 players. I try to join and it tells me the server is full.
I refresh all servers, go back to the same one, still 12 of 14 players and still get the Server Full error.
If I right click on the server, go to Info, then refresh just the server it will again say 12 of 14 players, I try to join and still says Server Full.
Is this a delay in the server pop reporting?
Is this just bug?
Is it that there are actually 2 players spectating taking up the final two slots, but they are not showing as part of the server pop, making it appear as if there are 2 free slots?