I’m trying to install the Python3.8 package (with the tutorial project) I seemingly successfully built at the ActiveState website… this produced for me a .msi install package… It runs till the end… then bombs out reporting “There is a problem with this Windows Installer package. A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor.”
(I had the same problem and received the same error msg when attempting to install Python 3.6.2 before this one.)
I suspected that my running Komodo IDE might be a problem… so I stopped that exe and retried the install - failed again with the same error msg.