Following up. This is a summation from Adobe on this issue. This is for Win 8.1.
1.Sign out from CC desktop application and Light room 5
2.End all the Adobe processes.
3.Try updating from CC desktop application. Updated and shows as up to date
4.Click on Light room 5.6 nothing happen.
5.Sign out from CC desktop apps .
6.End the Adobe processes
7.Delete the Light room cookie installer in program data>adobe>Light room folder
I think that last step is just as important,