I took my Pro license offline during the Beta program of ArcGIS Pro. Now that the software has been updated to 1.0, the Prerelease won't open and activate. The issue is my license was offline during the upgrade and now trying to boot up the new install of Arcgis Pro I'm getting an offline license error. Pulling up my account in the license manager doesn't give me an option to revoke: "has taken their ArcGIS Pro license offline. It cannot be reconfigured at this time."
Take a look at the last message in this discussion.
It's probably connected to taking the license offline without Administrator privileges.
The solution is described in the above mentioned discussion and involves resetting your Pro license through ESRI Technical support.