Are you still encountering this error? Please try to upgrad to the latest maintenance release of Tableau Server. There have been several fixes implemented for Tableau Server installation process: Tableau Server 2018.2.2 | Tableau Software
If you are encountering issues with the latest release of Tableau Server please open a case with the Tableau Technical Support Team. Support Case | Tableau Software
Hope this helps!
Cheers, Byrne, Patrick
Was this ever solved? I have the same issue when upgrading at get stuck at "Uninstalling restore services"