If you mean the buttons in the Header Pane, they can be customized with this add-on:

https://addons.thunderbird.net/en-us/thunderbird/addon/msghdr-toolbar-customize/

Please see image and upper right hand side.

Before this so called "upgrade" they had text..

Why in the world, do it with out having an onn/off etc...and then be forced? To get an add on?

Me? Age 63 paper tape programming started for me in the 70's, and then I was with MSFT Beta teams from DOS 3.0-6.22 All WinNT's then Wink2K up thru server 2003 etc..

It only shows icons if the Message Pane is too narrow to show text plus icons. Enlarge the pane or choose another setting in View/Layout.

Yes, but it is the same size window I always use it at for 5+ years...and same layout, so something there got changed in a css CSS or something that is not correct?

As the world thinks everyone is HiDef Monitors and I run 1360x768 for also same this box since 2015

I sure thank you as strange as all I did was the upgrade, then when it restarted it took it to this....and now I expanded, and weird as it eats up a little more space needed to show them

Again ty for reply Jim

I'm writing from a 15.6" laptop at 1366x768 and Classic View in TB. The icons and text are shown.

Here is another thing I noticed that lower right icon and message new then, I used to click on that and it would go right to that message

BUG as it no longer does... ;eave the wheel alone -smile- it was rolling fine

There are plans to enhance this area in a future version, roughly a year away. But it requires significant UI and code refactoring, so nothing further will happen during version 91.