This isn’t a problem, per se, with the PolicyPak CSE. This is a problem with the MSI database that contains the contents of what is registered or not.
You might see a dialog similar to this when trying to uninstall. And, even if we (PolicyPak) provide the previous version to you, its still likely that the CSE wont uninstall.
To fix and remove to enable a re-installation of the newest CSE:
Download MSICUU from this link: https://www.dropbox.com/s/02iin2rd4ns9qyl/msicuu2.exe?dl=0
Then launch it and select the CSE version and click Remove