Double-click the downloaded SQLSysClrTypes.msi file. You may be prompted for Administrator permissions.

Microsoft no longer prominently hosts SQL Server 2012 components on its main download pages, as the product has been out of mainstream support (ended July 11, 2017). However, the official download is still available via the archive.

Run as administrator, reboot, and retry. Also ensure Windows Installer service is running ( services.msc → Windows Installer → Start).

The installer may need to replace or register assemblies in the Global Assembly Cache (GAC).

The specific package you are looking for is part of the .

For current projects stuck on SQL Server 2012, it is wise to: