It's possible that the wrong version of Flash Plugin is causing this issue. Can you try to install the FlashAid Firefox plugin and run it once? It will attempt to locate and install the correct version of Flash Plugin for your system:
https://addons.mozilla.org/en-US/firefox/addon/flash-aid/
It's possible that the wrong version of Flash Plugin is causing this issue. Can you try to install the FlashAid Firefox plugin and run it once? It will attempt to locate and install the correct version of Flash Plugin for your system:
https:/ /addons. mozilla. org/en- US/firefox/ addon/flash- aid/