Check

It loads for me. Try [[Clear cookies and site data in Firefox#w_clear-cookies-for-the-current-website|clearing site cookies]] and [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems#w_disable-all-extensions|disabling your extensions]].

Please show a screenshot!

''<p>zeroknight [[#answer-1617710|сказал(а)]]</p>'' <blockquote>It loads for me. Try [[Clear cookies and site data in Firefox#w_clear-cookies-for-the-current-website|clearing site cookies]] and [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems#w_disable-all-extensions|disabling your extensions]]. </blockquote> Please show a screenshot!

Try to change the width/height of the Firefox window to force a redraw like worked in this thread. *[/questions/1428741#answer-1615278]

Does it still happen in a [[Profile Manager - Create, remove or switch Firefox profiles|new profile]]? An easy way to test a new profile is to install [https://aurora.mozilla.org Developer Edition] and see if it happens there or [[Refresh Firefox - reset add-ons and settings|refresh your existing profile]].