M$ knows of the issues with MEssenger. It is all over the News Groups. Just give them some time to sort it out. It is a problem with either the WLM & Yahoo merger or the servers. they are working to figure it out and get it sorted out ASAP.
I do not accept support questions via EMail, PM, IM or my G+ page!
Phone: LG Optimus G Pro
Running: Stock JB from LG with Nova Launcher