This issue can be caused by an extension that isn't working properly.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do not click the Reset button on the Safe mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode

If it works in Firefox Safe-mode then disable all extensions (Tools > Add-ons > Extensions) and then try to find which is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

See also:

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

Its because the website is not loaded completely..

Please reload the webpage while bypassing the cache using one of the following steps:

• Hold down the Shift key and click the Reload button with the left mouse key.

OR

• Press Ctrl + F5 or Ctrl + Shift + R (Windows and Linux)
• Press Command + Shift + R (Mac)

See if this helps solve the issues you had and please report back to us!

Спас сброс Firefox в его изначальное состояние. Параллельно исчезло еще несколько проблем. Спасибо всем!