In your Question Details > More System Details, I do not see the "Shockwave Flash" plugin listed at all. So it may well be blocked as being very out-of-date.

You can get version 18.0.0.232 on this page:

https://www.adobe.com/products/flashplayer/distribution3.html

In the first table, look for the row for "plugin-based browsers" and you can use either the EXE or the MSI installer.

After running the installer, open Firefox's Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. On the right side, look for "Shockwave Flash", particularly toward the bottom, and if necessary, change "Never Activate to either "Always Activate" to "Ask to Activate".

If you cannot activate Flash, click the "More" link for the plugin to check that it detected the updated version. If not, you might need to exit Firefox and start it up again.

Success?

Some Flash games do not start correctly in Firefox 40, but there is a "hotfix" available for that on the Add-ons site. Your Firefox should load it automatically if you haven't disabled updates, but you can load it manually if you like: https://addons.mozilla.org/firefox/addon/firefox-hotfix/

Does that make any difference?

Thank you. My concern is that it wont work with Windows 10 since neither the Adobe site or the Mozilla site said anything about Windows 10. Do you know that it will work with Windows 10?

As far as I know, everyone who is using Flash on Windows 10 is using that same plugin that is for Windows XP and higher. Does it work exactly the same on Windows 10 as on earlier versions? I have no idea, but what's the alternative?

I have been freezing constantly since changing to Windows 10.

Hi jjcemery, thank you for starting a new question about your freezes here: https://support.mozilla.org/questions/1083121

HOTFIX doesn't work on ff 44 so where do I go ? haven't been able to get onto Farmville since win10; have set and reset flash over and over again; chrome is totally out of the question as they have even worse flash problems; will check the question link you give above, but this is really annoying.

MY BAD !!!!!! turns out I no longer had JAVA installed, no idea why not, always had it but was missing : reinstalled and farm loading lots better even though not very fast but that's a zynga problem.

thnx for suggesting JAVA somewhere.

-)