I'm using Windows 10, Firefox 57.0.4 and I'm trying to turn off hardware acceleration in the Flash player. But the settings window is unresponsive.
try to open another tab and go back to your settings.
No matter how many I open, it doesn't work. I've had this problem once before and I fixed it, but I can't find those instructions again.
If you're opening up the Settings option from the context menu, you'll want to make sure that you're not opening it up over a video or an animation that's moving. We do a bunch of stuff to ensure that you can see those dialogs (e.g. an attacker isn't crafting content over the top of the dialog that might trick you into changing security settings when you think you're shooting something in a game, etc.), and if we can't validate that we're unobscured and on top, we won't accept your clicks. I think that's what's going on here.
There *is* a native Flash Player settings pane in the Windows Control Panel, but you can't change hardware acceleration settings there.