Hmm, usually setting browser.backspace_action to 2 (or a higher number) will set Firefox not to do anything when you press Backspace outside of an editing field. Your about:config should look like the attached when you paste the preference name into the box there.

In theory, a website could have its own code for what to do when you press the Backspace key. If you notice this problem on particular sites, that would be worth investigating further.

I guess that is the problem, mine is set to zero, will not change from zero, is stuck on zero. Please HELP !!

(If u cant see the uploaded screenshot let me know, it does not show up on the preview)

Sometimes we see a lock at the left end of a row in about:config, but fortunately yours does not show that it is locked. Does an editing field open if you click the "pencil" button on the right or double-click the zero?

Note that in Firefox 87+ browser.backspace_action will default to 2 on all supported platforms (was already 2 on Linux, now then also on Windows and Mac).

• https://searchfox.org/mozilla-beta/source/browser/app/profile/firefox.js#835
• bug 1041377 - Disable Backspace as a shortcut for navigating back in history

Hi jscher2000, Yes a dialog box opens, with the pencil, and I change the value to two and close the window. Then nothing changes.... Sorry if I appear stupid, there is no "save" option or button and don't know why it wont stay at two.

Hello cor-el, I thought I read that it was permanently changing on FF 86+, but I could be wrong, or the person that wrote the article could have typo-ed or been mistaken.

After changing the value to 2, the only action to save the change is to either click the blue checkmark button or press Enter. Then the row should turn "bold" indicating that it has changed from the default. (In Firefox 87, if 2 is the default, the row won't be bold any more.)