Fóram Tacaíochta Firefox

I just got my upgrade from Firefox86 to Firefox90 working, but the tab bar is completely missing.

I still use "old-style" FIrefox. From top to bottom: File/Edit/View menu Search bar Bookmarks Toolbar Tab bar

(yes, I AM old. I've been using Firefox since Version 1 and this particular style works for me, developers be damned.)

The tab bar is completely missing. Firefox knows how many tabs I have open (it warns me when I try to exit) but doesn't show any. The area that the Tab Bar used to occupy is simply empty.

Any ideas on how to fix? (Yes, I have done the Google.)

I just turned off AdBlock Plus in the Add-Ons screen and downloaded ublock origin to try it out. There is no icon for this new plug in to be found anywhere. I can manually go in and change the settings on this plugin in the add-ons screen but there is no icon anywhere to go in quicker or to show a report of how many items were blocked. When I try to Customize my toolbars, the icon is not available there either. The nearest threads I can find on this topic are from 2018 and their solutions are very basic use. Yes, of course I restarted the browser. TIA.

uBlock Origin: 1.39.0 Firefox: 87 filterset (summary):

 network: 83588
 cosmetic: 80376
 scriptlet: 18231
 html: 598

listset (total-discarded, last updated):

 added: 
   adguard-annoyance: 47817-586, now
 default: 
   ublock-filters: 30169-27, now
   ublock-badware: 3455-1, now
   ublock-privacy: 182-0, now
   ublock-abuse: 70-0, now
   ublock-unbreak: 1706-0, now
   easylist: 61109-543, now
   easyprivacy: 26327-473, now
   urlhaus-1: 10038-0, now
   plowe-0: 3699-3, now

filterset (user): [empty] modifiedUserSettings: [none] modifiedHiddenSettings: [none] supportStats:

 launchToReadiness: 1924
 launchFromSelfie: false

All of a sudden I'm getting the Yahoo maiil ID changed to Google Mail with out any authorisation on my part ? I know Google owns Yahoo. I use Yahoo mail all the time and Yahoo is my ID for many applications so why has this happened ? If something like this can change unknowns to me does this mean that Google has control of my MAC and FireFox and its content .??