Flash 23 hangs in Firefox

I seem to have found the code to fix it. There were several posts among many suggesting this fix but this YouTube helped me implement the needed change. It was all about adding a 'ProtectedMode=0' line to a .cfg file in the Flash folder. This may somewhat add vulnerability but the Flash add-in on Firefox was useless otherwise.

I wasn't sure this fix would apply to the current version of Flash that I installed (V23) but it seems to have done the job. Maybe this will help others or maybe someone knows of another option.

https://www.youtube.com/watch?v=IYX9i4goEkM

I see many others have or have had the same problem but the solution isn't clear, at least to me. Is this a Adobe V23 Flash compatibility problem with Windows 7 and / or Firefox 49 which is what I am using.

According to the Adobe install site, V23 of Flash is supposed to work on Windows 7, and I assume all versions of Firefox (again, I have V49).

Any insights would be appreciated...........thank you.