Also same problem i have now with other MP missions aswell. Mission loads, then i choose soldier type and after that game tries to do something but freezes.
Yesterday before todays patch i had no issues at all.
none of following helped:
Doesn't happen here.
Anyways this would be a mission-related bug, not game related, hence you should report it to its dev not to BIS.
/downvoted
Like Kid, it's a mission related problem... Try to create a server and play the BIS coop mission, I'm sure it's working for you.
After latest patch it seems to be working fine.
I posted this issue, because it was creating logfiles, so i thought its a crash