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?

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP in front of the numbers/letters, click it and select Submit.

Using your mouse, mark the most resent 7 - 10 crash reports, and copy them. Now go to the reply box below and paste them in.

В безопасном режиме работает нормально. В about:crashes нет критических ошибок в период когда начались проблемы. Flash Player обновлен Version 18.0.0.203 Браузер был удален полностью и заново перестановлен. Проблема не решилась

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.

It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac:<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is detective.

Проблема была в апаратном ускорении, при отключении его браузер начал работать нормально. Спасибо за помощь!

You can try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can check if there is an update for your graphics display driver and check for hardware acceleration related issues.

• https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration