Does the attachment pane appear in safe/troubleshoot mode (hold Shift when launching TB)? If it does, the layout might be broken.

Near as I can tell, the easy access to save attachments is gone. Now you have to select the desired message from the list, and scroll all the way to the bottom of that message to find the huge attachment icons. When you get there you'll find an attachments download button that will download all the attachments to a single folder, or you can go to the download button next to each attachment and download them one at a time. Apparently they did away with the ability to highlight and right click to save attachments from the bottom of the pane. Sigh. This is so much more clunky. I wish we could revert to the previous release.

Problem solved. I did what you suggested and the size of my top pane was too large so the bottom of the email I was reading had fallen off the bottom of the screen! Sorry I'm not very techy!

@BarnRat1 I have the same complaint. I would like to be able to view attachments from the message preview window, rather than having to open the full message. This is no longer possible in Thunderbird 91. Maybe it's only a couple of mouse clicks but it feels very annoying.

Never mind. There's an easy fix - just make the bottom part of the message preview window taller. The attachment bar at the bottom got cut off, probably because I recently enlarged a bunch of fonts. (It might be nice if the attachment bar automatically displayed, though.)

The old version is still easier, no need to expand the preview window, you could see the attachment with any size of preview window