To diagnose problems with Thunderbird, try the following: Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender.

Thanks Matt, Did the safe mode thing. This clarifies the issue a little but... First of all the menu items File etc are not at the top of screen so are OK as expected. Second the size buttons do not appear as I would expect. (See next screen shot).

Dave

The menu bar has been a part of the tab in Thunderbird since about Version12. Just as it is in Firefox. I hated it at first, but got used to it.

On the toolbar > Options > advanced > General and try toggling the use hardware acceleration option.

Is there a better view one way or the other?

Close but no cigar. (Am I still allowed to use this saying if the world has gone prohibition on tobacco???).

Thanks Matt, No change in File-Help dropdowns. Hardware acceleration was unticked. I ticked it and restarted TB. No change. Amusingly, on exactly the same computer&config, FF with walnut displays the File-Help dropdowns correctly.

In FF the words are centred approx half way between the top of the tab and the top of the display area. And if you hover over the dropdown it highlights the thing with all corners rounded except the bottom left. The highlighted area almost sits on the top of the tab.

In TB the highlighted bit appears to be higher. There is a distinct gap between the highlight and the tab, The word is shifted up so that the lower case body of the word is almost at the edge of the display area. The rounded top of the highlight is way off the display.

Thanks Dave

Looks like the Title bar is not enabled, so it has that cropped top look.

Try this: Tools > Options > Advanced > General tab click on 'config Editor' button

In top search type 'title' look for this line : mail.tabs.drawInTitlebar double click on that line to toggle the Value from 'True' to False

close window - top right X click on OK

Did enabling the title bar fix the issue?

Thanks Toad-Hall, That certainly got rid of the cropping. But all it did was to move the thing down the screen. There is still the gap between the top of the tabs and the bottom of the menu items when highlighted. The default is that titlebar not displayed.

Thanks Dave