It is okay if my answer is "Maybe"?

In Firefox 58+, if you check the Permissions panel of the Page Info dialog, there is an option to prevent the website from overriding keyboard shortcuts. However, I don't have Firefox 56 handy to see whether it had that option.

While you are on the site, you can call that up using any of these:

• right-click a blank area of the page and choose View Page Info > Permissions
• (menu bar) Tools menu > Page Info > Permissions
• click the padlock or "i" icon to the left of the site address, then the ">" icon, then More Information > Permissions

Scan/scroll down to "Override Keyboard Shortcuts" and uncheck the "Use default" box, and then select the permission you prefer. In some versions of Firefox, there is a bug where setting Block disables the Backspace button in a form field, so you have to select text and delete it using the Delete key. That may or may not be a crucial issue for the sites where you want to block changes.

If you try this out, does it work?

Also, depending on how the site's scripts work, there may be a way to inject a counter-script to strip away its special key handling. You could investigate a user script as an option for that. These are two sites where people search for and request user scripts, with varying degrees of success:

• https://greasyfork.org/en/forum/categories/script-requests
• https://openuserjs.org/corner

It might not be practical for complex sites.

Also, since your Firefox identified itself to the forum as an out of date and no longer supported version:

The current releases of Firefox are:

• Regular release: 63.0 (Installers)
• Extended Support Release (ESR): 60.3.0esr (Switch to Firefox Extended Support Release (ESR) for personal use)

If something is holding you back from upgrading Firefox, please let us know so we can suggest solutions or workarounds. Version 56 is not secure.

jscher2000 said

Also, since your Firefox identified itself to the forum as an out of date and no longer supported version: The current releases of Firefox are:

• Regular release: 63.0 (Installers)
• Extended Support Release (ESR): 60.3.0esr (Switch to Firefox Extended Support Release (ESR) for personal use)

If something is holding you back from upgrading Firefox, please let us know so we can suggest solutions or workarounds. Version 56 is not secure.

Firefox 57 killing most addons (and reducing the surviving ones to bare bones) is the main reason why I stayed on 56. Most people I know think the "new firefox" is worse, as it constantly crashes with out of memory errors or just hang/slow down for them. So I'm not the only crazy one staying in 56.

Thanks for the replies, sorry for asking.

It is sad to lose old extensions, but the depth of loss varies considerably based on which ones you need versus the capabilities of the replacements.

I'm not aware of out of memory errors being any worse in more recent versions of Firefox. If you encounter that problem, please post a new thread.