Operating System Version: Windows 8.1 Enterprise (AMD64)
Web Browser and Version: Internet Explorer 11, Chrome 54, Firefox 50
Flash Player Version: Flash Player ActiveX 126.96.36.199
Problem Encountered: Unable to install Flash Player ActiveX 188.8.131.52 due to an apparent error in the MSI.
Error Message Received: 1722. There is a problem with this Windows Installer package.
I can also provide the MSI verbose install log if necessary.
As of Windows 8 Microsoft embeds Flash Player in IE and all Flash Player for IE updates are released by Microsoft, not Adobe. You'll need to run Windows Update to update Flash Player for IE on Windows 8.1
The Flash Player distribution page, where the MSIs are posted to includes the following comment:
Note: As of Windows 8, Microsoft embeds Flash Player in Internet Explorer, and Edge browser in Windows 10. Flash Player ActiveX installers are for Windows 7 and below.