I am having the same problem. I have had a friend use my account on his pc with no problems.
Tried:
- Rebooting
Reinstalling wlm
Uninstalling MP!L
Disabling the firewall
These have no affect on the error and i am unsure what to do next except contacting the messenger support.
Trev
Edit: I just look at
THIS POST and opted out of the beta. Its now working