Portable Mozilla Firefox 43.0.2 began to catch on my Windows 7 (x64) with messages "Shockwave Flash inactive" The previous version (Firefox 42) was OK. By checking the difference between the two versions, I found a new "Firefox (x64)" folder in the "App" folder that is inside the program. I deleted the (new) folder "Firefox (x64)" and Moxilla Firefox 43.0.2 now works great.
You need to update flash on the host system to ensure it is the latest version. Much older versions are 32-bit only. Firefox Portable now uses both 32-bit and 64-bit depending on the system.
Sometimes, the impossible can become possible, if you're awesome!
The Flash Player is updated. But I run the browser (Internet Explorer, G. Chrome and Mozilla Firefox in Sandboxie. The 43.0.2 version only worked after I turned out the new Firefox(x64) folder in App. Searching the internet I read about the withdrawal of Mozzila the x64 version, then I decided to delete the Firefox(x64) folder . Now everything is OK, running very fast and in Sandboxie(x64).
You'll need to force 32-bit to get it working with Sandboxie: https://portableapps.com/support/firefox_portable#32and64
Deleting the 64-bit copy has the same effect but must be done after each upgrade.
Note that we neither support nor recommend using Sandboxie with any of our apps. It's buggy and has a tendency to kill our launchers and cause data loss.
Sometimes, the impossible can become possible, if you're awesome!
I stopped using Firefox Portable. The 43.02 version and the last 43.04 (with the x64 folder) act strangely in Sandboxie. The Sandboxie warnings box does not issue warnings for new downloads. I think this indicates the new version of Firefox (43.02 or 43.04) completely lost privacy. While is not cured I think it is most recommend to stop using Firefox Portable.
As mentioned above, you'll need to force 32-bit full time. Either that or stop using Sandboxie. Sandboxie has bugs that affect the way the portable launcher work and can cause data loss that have been known for years. That's why we don't support running within it.
Sometimes, the impossible can become possible, if you're awesome!