Instability when in fireteam

Friend joined on me for a bit and him joining on me caused my client to freeze. I had been playing for hours without problem until now.
Reload game, friend joins on me again, game crashes to desktop.
Attempt #3 and it works for a game and freezes again.
Attempt #4 same as above.

I know this is a beta… but I’m not happy to see MCC problems in this game…