Hello,

Can you try disabling hardware acceleration?

1. Click the menu button New Fx Menu and select Options.
2. In the Firefox Options (or Preferences) window, click the Advanced tab, then select General.
3. In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
4. Now, restart Firefox and see if the problems persist.

  *  Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Separate Issue: Update your Flash Player Version 18.0.0.203
https://www.adobe.com/products/flashplayer/distribution3.html Note: Windows users must download the “Internet Explorer” and “Plugin-based browsers” installers.

See if there are updates for your graphics drivers https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options) key, and then starting Firefox. Is the problem still there?

Unchecking " Use hardware acceleration when available" checkbox did not solve the problem.

FredMcD said

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options) key, and then starting Firefox. Is the problem still there?

Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Yea....Safemode didn't show much problems.

Firefox Safe Mode? Or Windows?

Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes). If the problem goes away, that tells us one thing. If it does not, that tells us something else.

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Restart Firefox. Are there any problems?

Firefox Safe Mode ........ and unchecking 'Use Hardware Acceleration' doesn't solve the problem.