I don't use flash anymore, just html 5.
This is the best fix I have.
Lets say you use firefox and it isn't working right any more.
This is why, it has corrupted files.
If the usual emptying of all cached history data doesn't work you
could try this.
Delete everything in this folder C:\Users\you\AppData\Local\Mozilla\Firefox\Profiles\ .default\cache2\entries
If that doen't work,
First uninstall the program but that won't fix it.
Next you have to make visible all hidden files and folders in folder options.
C:\Users\you\AppData is the location where the corrupted files should be.
There should be 3 folders in AppData and you will have to look in each one
for firefox files and folders and delete them.Also look in common folders
in AppData and the program files folder and delete firefox out of there also.
If you are sure you have deleted everything then reinstall firefox.