For some time now Adobe Flash has been causing Firefox to freeze for a few seconds and then comes up with a message that Flash has crashed. I don’t know why I lived with it for so long but here’s how to fix it and stop it from happening.
First update Flash to the latest version. You can see your version vs the current version here. If your version is out of date go here to update.
Next go to any page that uses Flash like this one. Right click on the Flash object and select settings. On settings click on the tab on the far left (the little monitor) and uncheck “Enable hardware acceleration” then click close.
Restart Firefox and your Flash crashes should stop.
This method is best combined with disabling 3D in nVidia’s display driver.
In light of recent Adobe vulnerabilities it is advisable to disable Flash entirely.