Hi Milena,

In you adres bar copy paste the following: about:config

The browser might warn you to proceed with caution, accept this and continue (if not you can proceed to the line below).

Copy paste the following: accessibility.blockautorefresh

See if this option is set to True. If it is set on true toggle the button on the right and check if the value has changed to false.

If the above doesn't help, please provide more detailed information.

Regards,

Shred

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems