Thanks for the reply and help! This issue had been annoying me for such a long time. I had no luck with solving the problem by repairing Rhino 6 through Windows>Programs before. And I wasn’t able to uninstall Rhino 6 as well. I had to continue to use the old version, which was fine with me. Recently, I found that someone posed a similar issue in this forum. That solution solves my problem (the link: Rhino 6 update/install error rhino.msi: -2147023293 [SOLVED]).
The key point is using Microsoft’s troubleshooter to uninstall three things down below:
- Rhino6
- Rhino Engine Installer
- Rhino Language Pack
After that, the latest Rhino 6 can be installed successfully. As I can tell, most of the old plug-ins and settings are still there. Hope this will help some people that have the similar issues.