One quick fix (well work around) is to open up your internet hardware settings and disable your network card. Then re-enable it. That will reset your IP. Then you can log back on as normal and the "mex Sessions" error will be fixed.
NOW as to what causes it, can't tell ya, that's for the DEV team to fix.
BTW any chances on how the "session invalid" error is coming?
NOW as to what causes it, can't tell ya, that's for the DEV team to fix.

BTW any chances on how the "session invalid" error is coming?
