Please ensure to backup any custom family or template files prior to following this procedure:
Before reinstalling Revit products
To verify that an anti-virus program is not still running in the background as a TSR (Terminate and Stay Resident Program):
Windows XP, Windows Vista and Windows 7
Updated SDKs for Revit 2015 R2 and UR4 - The Revit SDK available from the Revit Developer Centre has been updated for Revit 2015 R2 and UR4, aka Revit 2015 Release 2 and Revit 2015 Update Release 4....
13 hours ago