The official method is to use Adobe's uninstaller to strip all Flash off your system and then reinstall. See: Flash Plugin - Keep it up to date and troubleshoot problems.

The hack that usually works is simply to delete the old DLL file.

To find the path to the file, you can use the about:plugins page (type or paste about:plugins in the address bar and press Enter to load it).

Use Find (Ctrl+f) to look for npswf which is the beginning of the file name of the Flash DLL. This should point you directly to the location of the Flash 16 DLL from where you can delete it. If Adobe uses the same location on Windows 10 as it does on Windows 7, that would be here:

C:\Windows\SysWOW64\Macromed\Flash

Please don't delete other files in that folder without researching what they are for.

First, could you test something? I have a page that lists out your enabled plugins, first by name, and second by their mime-types:

https://jeffersonscher.com/res/plugins.html

In the lower section, if you look for application/x-shockwave-flash does it show that the script is being pointed to the newer or older version of Flash? If it's the older version, there's your trouble.

I am pleased to say that I have deleted two files referring to the old 16.0.0.235 plugin and now have a clean Plugin Status.

Many thanks for your help.

Regards Mike