hello turzo, you're using a very outdated version of the browser. first please update firefox to the latest version and see if the issue is still present there...

Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.

(If you're not using it, switch to the Default theme.)

• Open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.

Once you get the pop-up, just select "'Start in Safe Mode"

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.

To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

NOTE: Some content on Facebook can be copy protected. Facebook can choose what you can copy and what you can't.

NOTE: Like philipp said above, please update you browser as soon as possible.

See also;

• RightToClick: https://addons.mozilla.org/firefox/addon/righttoclick/

Note that you may not see the normal background of selected text if the background is a PNG image with a white background color. You may only notice a slight change of the text color.