There is an add-on to again make a the shortcut for copy link. I can't give you a link to it.

No need. As I say <cmd L> works fine. It would be good if the shortcut keys were shown in the right click popup.

Gosh it is getting hard to comment. As I reported above, there is a login bug, and it thinks (mistakenly) that cookies are disabled. I have to quit Firefox and restart to successfully log in.

Is there no interest in my very huge list of links that now fail under Firefox? All was fine, I reckon, until 64bit MacOS Catalina.

I prefer Firefox as I have got so used to it and its many (often undocumented) shortcut keys.

I spend all my working life analysing web pages and html source. It is becoming more and more difficult using Firefox as I often have to switch to Chrome/Safari to do my work. It can actually be critical, as if a previously loaded webpage changes its content, then the source view content remains unchanged.

The error message said 'Cookies must be enabled' and I couldn't get further. Cookies *were* enabled! I shut down Firefox, and re-opened, and all was then OK.

Hmm, I don't know why that happened or why restarting helped. File locked up??

. Web pages with scripts are often completely blank. . Pop-ups are often blank. If not they often don't work, like (critically) Ebay login.

What have you tried so far to fix this? I'll give general suggestions at the end.

. View source (CMD U) works for new pages. However doesn't update if the source page changes.

View Source shows the page as it was served originally and doesn't reflect changes made by scripts after the initial load. To see the modified state of the source you can Select All (Command+A), then right-click/Ctrl+click and choose View Selection Source. This can be slow to load because Firefox is rendering out the live DOM.

A silly one is that the keypress to 'Copy Link' was deviously 'A', but not shown. It has now changed to 'L' and still not shown. Why? I very much prefer Firefox, and all the many shortcuts are memorised (well bar 'L' (8-)# )

On Windows, the "accelerator" key for a menu item is underlined, or maybe I enabled that to make Windows 10 look more like older versions. It certainly is handy.

The reason it changed from A to L is that the word Location was removed (and that's where the A came from).

If you are getting a blank page, please make sure the redirect block is turned off:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box in the page, type or paste access and pause while the list is filtered

(3) If the accessibility.blockautorefresh preference has a value of true, double-click it to restore the default value of false

If a site is generally known to work in Firefox, these are standard suggestions to try when it stops working normally:

Double-check content blockers: Firefox's Tracking Protection feature, and extensions that counter ads and tracking, may break websites that embed third party content (meaning, from a secondary server).

(A) The shield icon toward the left end of the address bar usually turns a bit purplish when content is blocked. Click the icon to learn more or make an exception. See: Enhanced Tracking Protection in Firefox for desktop.

(B) Extensions such as Adblock Plus, Blur, Disconnect, DuckDuckGo Privacy Essentials, Ghostery, NoScript, Privacy Badger, uBlock Origin or uMatrix usually provide a toolbar button to manage blocked content in a page. There may or may not be a number on the icon indicating the number of blocked items; you sometimes need to click the button to see what's going on and test whether you need to make an exception for this site.

Cache and Cookies: When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, click the lock icon at the left end of the address bar. After a moment, a "Clear Cookies and Site Data" button should appear at the bottom. Go ahead and click that.

In the dialog that opens, you will see one or more matches to the current address so you can remove the site's cookies individually without affecting other sites.

Then try reloading the page. Does that help?

Testing in Firefox's Safe/Troubleshoot Mode: In this mode, Firefox temporarily deactivates extensions, hardware acceleration, any userChrome.css/userContent.css files, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is running:

You can restart Firefox in Safe/Troubleshoot Mode using either:

• "3-bar" menu button > Help > Troubleshoot Mode... (before Fx88: Restart with Add-ons Disabled)
• (menu bar) Help menu > Troubleshoot Mode... (before Fx88: Restart with Add-ons Disabled)

and OK the restart. A small dialog should appear. Click the Open button (before Fx88: "Start in Safe Mode" button).

If Firefox is not running:

Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.) A small dialog should appear. Click the Open button (before Fx88: "Start in Safe Mode" button).

Note: Don't use the Refresh without first reviewing this article to understand what will be deleted: Refresh Firefox - reset add-ons and settings.

Any improvement?

Many thanks for the long and well thought out reply.

. Viewing source Your solution of course is slower. I view one particular page (my generated debug page) hundreds of times a day sometimes. There used to be no issues. The page has no scripts. It is usually plain XML code.

. redirect block Now turned off.

. clearing cookies/cache I didn't know about the 'lock' option. I have been doing that up to now globally.

There are also 'shield' options.  

Thanks for that.

I still can't log on to Ebay. 'Continue' is greyed out even with my email entered. I turned off 'Enhanced tracking protection' via the 'shield' and three other login options appeared. I chose 'Apple' and went through two part authentication - seemingly successfully. I then got to a window 'Ebay and Apple ID. Add your email to create an eBay account or link to an existing one.' ... but 'Continue' is greyed out. I deleted cookies, and turned off 'Enhanced tracking protection'. The irony is that login works first time under Chrome and Safari.

The underline for shortcut keys would be good in Mac Firefox. I have to guess.

I will report back after a bit of use/experimenting.