"Due to an expiring certificate no Mumble 1.2.2 or newer released before today (15.01.2012) will work on the Windows Platform after 15 January 2012 11:36:47 GMT. If such an outdated Mumble is launched after that date the error message “A referral was returned by the server” will be displayed by Windows and Mumble will not start."
There are 3 different ways to download the fix located at the blog.mumble.info link below.
http://blog.mumble.info/important-update-to-mumble-1-2-3a/
I personally used the 3rd one because all you have to do is download a mumble.exe file, go into your program files then into the mumble program files and move the new mumble.exe file into that folder to replace the old one.
Thu Dec 19, 2013 2:14 am by 
