You may run into problems doing certain actions inside Revit during the month of January. You may be unable to open files saved from older releases. You may have trouble editing groups, schedules, interacting with the project browser....
Temporary Workaround: Set system time to any other month than January.
Permanent Workaround: Autodesk is working on it. I hope it gets completed prior to February when the need is moot.
Discussion at AUGI
Autodesk Support Services