If you right click the Back button, can you access previously viewed pages that way?

Yes, right click does allow back-up through links. I have my center mouse button configured for back-up and of course that does not work when the buttons are grayed out. Navigation used to be so sweet. Now that is much harder but we've got all the menus and toolbars rearranged. Great!!

I have this same problem along with some others. My forward/back button are grayed out upon opening FF.

Issues with the Back button not working properly can be caused by the McAfee SiteAdvisor extension.

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

If the back button is greyed out, then it simply means there isn't a page to go back to within that tab. In that respect, Firefox doesn't add your history i.e. the pages you just visited in the current session to a new tab. See screenshot.

The bottom half of the picture shows the history from the session in the next tab.