These days with most browser vendors blocking Flash, these detection scripts are used similarly, as well as by the browser to prompt the user to allow/unblock Flash.
If so, in the old days (before browser vendors disabled/blocked Flash by default), if the plugin was installed Flash content would just play, if the plugin was not installed, the user would be notified to install Flash. When developers include Flash content they also include Flash detection scripts that are used by both the content & the browser to determine if the user has the required plugin installed. The behaviour your experienceing is content related. Give me as SIMPLE as an answer as you can give me: Is there a Flash Player that will work in Firefox 71.0b7 (32bit)? I was going to create a program for people to use the site I’ve been using for years but now I can’t because I can’t even get into it anymore. When FF Updated their browser they gave me the Firefox 71.0b7 (32bit) version and everything was working great until I wanted to go to the site I’ve used for years and it will not work with the Flash Player. I was going to download the 64bit version of Firefox (it has a lot of bugs) but then I find out that Adobe Flash won’t work in the 64bit version of Firefox. I can open the same site that I’m trying to open in Firefox 71.0b7 (32bit) in Internet Explorer 11 but, I don’t like IE because it’s not too safe. I found ways to lessen the NPAPI plug-in (that doesn’t work) NOTHING DOES.
I am running Windows 7 Ultimate on a 64bit Operating System and when Firefox updated to Browser 71.0b7 (32bit) the site that I’ve been using for years now I cannot get in because when I open the site it says “Run Adobe Flash” so, I click it and ANOTHER pages pops up asking me to “Run Adobe Flash” and I do click on it and nothing happens, this is why I‘ve been doing a lot of research on Google (ALL DAY NOW) as to why this is happening and basically it is saying that “Firefox” now Mozilla adds NPAPI plug-in sandbox to Firefox which disables the Flash Player I need. Good day, I’ve been trying to get a fix for this ALL DAY now and everything I’ve read seems that there is NO FIX because Firefox (the browser I use the most) now BLOCKS Adobe Flash.