- In a new tab type in the address bar about:config and press enter
- If you get a warning about “Voiding your Warranty” click the I’ll be careful, I promise button to continue
- In the Search box type context
- In the list of preferneces that show below located and dobuble-click dom.event.contextmenu.enabled to change the value to false
- Close the about:config tab
- Return to the site/page that was preventing you from right-clicking and try now. Note: You may still get a warning about right-clicking not allowed, but the context menu should appear now.