On my FE, the number of players is fixed at whatever the cstarena.cfg is set for and grayed out in the dialog.
When selecting a terrain, the dialog shows the new selection but I'm stuck with a different one, one I first opened tonight and also used before the last patch 3.03 p1. So far it always opens with avachanl even though the cstarena.cfg file correctly confirms a different terrain selected.
When I use CM Shutdown, it fails to shut down the room.
Apparently, Jaeger didn't have these problems while another players said he was unable to create a room.
Here's one of my cstarena.cfg files.
0x00010000,VERSION
test
avasml
16,MAXUSERS
-1,TEXTURE SET