Seems to be that just since last night I can't join any servers.
No matter what happens it will freeze just after the loading screen between the squad selection screen and the briefing screen for a few seconds then show up a "receiving mission files" loading bar without ever starting from 0% (it will just automatically be at ~95%).
Upon the "receiving files" bar showing up the game will lock up entirely and when ctrl+alt+del is used the "ArmA III Alpha has stopped working" box will be the first thing you see.
Happening on every server I try joining now. {F17580}