With the 108.0.2 update, I am limited to a single tab operation on my desktop computer. I have been using Mozilla since the original Netscape browser, but now I have had to move to MS Edge as my primary browser. Most disappointing! Updating to 108.0.2 on my laptop went normally, with multi tab capability. Both computers are Win 10.
Could you explain the situation on your desktop installation of Firefox in more detail:
What happens if you press Ctrl+T to open a new tab. You do not get a new tab, or the tab bar doesn't show both the old tab and new tab?
Are you ending up with multiple separate windows instead of having your tabs together in a single window?
Trying to direct a link to a new tab using Ctrl+click or middle-click (using the mouse scroll wheel) doesn't succeed and the link opens in the same tab?
What I should have said in my original post is that I have a NO TAB BAR situation. If I do a Ctrl+T, the page I have open is replaced by new page default content. If I click on a link, my open page is replaced by the linked page. No tab(s) ever show. No new windows. I have reinstalled Firefox 108.0.2, same results. 108.0.2 installed on my other Win 10 computer works normally.
If you create a new window using Ctrl+N, does it have a normal tab bar?
If that one also is broken:
It usually is impossible to accidentally or intentionally remove the tabs bar, except through external tweaks. Assuming you aren't using an optional userChrome.css file to override the normal toolbar layout, you could try the "Restore defaults" button in the Customize panel and see whether that helps: https://support.mozilla.org/kb/customize-items-on-firefox-new-tab-page
I have deactivated a userChrome.css and updated FF to 109. I am now seeing transparent tabs above the task tray, in different positions according to which open page I have selected, but only one tab at a time is visible. What good is one tab at a time? I don't see anything in Tabs Preferences to solve the problem. I expect I'll work this out in time. In the meantime, Tree Style Tabs is an acceptable workaround. Thanks again for your help.
I am now seeing transparent tabs above the task tray, in different positions according to which open page I have selected, but only one tab at a time is visible.
Do you mean above the Windows task bar (not normal), or above Firefox's main toolbar (normal)? Either way, tabs shouldn't be transparent. If you switch to one of the other built-in themes (System, Light, Dark), does any of them show the tabs normally? https://support.mozilla.org/kb/use-themes-change-look-of-firefox
Yes, above the Windows task tray/bar. I'm pretty sure tabs on the bottom of the page is a recent new feature of FF, including the transparency feature.
I just got around to installing Firefox 109, and tabs still look the same as Firefox 89-108 on mine.
Are you sure that some kind of customization from your userChrome.css file isn't still running? Do you use any startup scripting AKA userChrome.js scripts?
Update: I previously noted that that I deactivated userChrome.css. That was in about:config. Now I have gone into AppData...Firefox profile and found a userChrome.css file, which I renamed. That did the trick, after a restart. I now have tabs back on top. You were on the right track with the Chrome file. Many thanks.