Flash player not installing on Windows 10 for Firefox

<edit>

To troubleshoot, we'll need to obtain the online installer log files, Adobe_ADM.log and Adoge_GDE.log saved at C:\Users\<YourUserID>\AppData\Local\Temp\Adobe_ADMLogs and upload teh files to cloud.acrobat.com/send using the instructions at https://forums.adobe.com/docs/DOC-7161​ or some other file sharing service of your choice that doesn't require account log-in to access the files.

Note that AppData is a hidden directory.  If it's not visible see, https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

This is the online/shim installer, which is a ~1 MB file that downloads and installs Flash Player silently in the background.  The file does delete itself after execution (successful or not).