
Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause. If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. When the Firefox Safe Mode window appears, select "Start in Safe Mode". (you may need to specify the Firefox installation path e.g. On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode.On Mac: Hold the option key while starting Firefox.On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.If Firefox is not running, you can start Firefox in Safe Mode as follows: Click the menu button, click Help and select Restart with Add-ons Disabled.If Firefox is open, you can restart in Firefox Safe Mode from the Help menu: Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).

If that doesn't help, try Firefox Safe Mode to see if the problem goes away.

installed Firefox Setup Stub 34.0.5.exe-screen flickers, reverts to Firefox Setup 21.0.exe now.ff starts flickering the screen black when I click play on videos imbedded to sites.

ANGLE (AMD Radeon(TM) R6 Graphics Direct3D11 vs_5_0 ps_5_0) adapterDrivers: aticf圆4 aticf圆4 aticf圆4 amdxc64 aticfx32 aticfx32 aticfx32 amdxc32 atiumd64 atidx圆4 atidx圆4 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64.adapterDescription: AMD Radeon(TM) R6 Graphics.
