URL is?

Could you test in Firefox's Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox. Sorry, on Mac, you hold down the option/alt key instead of the Shift key.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

That worked. Is there a way I can tell which add is causing the problem?

Hi Hilgy, three of your extensions can block web page content, so you could start with seeing whether those allow you to make a site-specific exception: Adblock Plus, Disconnect, Google Disconnect.