I'm newly having the same kind of problem than you are, but only since tonight.
More precisely I get a game freeze (with a said error log requiring popping out Task Manager to close) when I'm trying to connect to the last person in connecting log, which now always fails, instead of getting the usual failing to connect or booted from the NAT facilitator.
And once my game didnt recognize my account too, it was only transient though. Whether this is due to the fact that I have changed its name end of last week (another problem already discussed elsewhere) and it hasn't still been changed, I cannot know.
My game worked actually pretty well this weekend.