Hi, Renee. You're just looking at the chat window instead of the mail window. And you seem to have the spaces toolbar disabled so there is no visible way to switch functions. Either of these things should work:

1. Go to the main menu and click View - Toolbars - Spaces Toolbar. Then click on the mail symbol.

2. Hold down the control key and press 1.

Then either leave the spaces toolbar visible so you can fix this in the future or remember control+1.

You could also show the main toolbar all the time and have a button for the spaces toolbar there. (I don't know how you have hidden your main toolbar. I do not see any way to hide mine.)

Thank you for the reply. Unfortunately, nothing changed as I turned the View for the Spaces Toolbar off and on. I have no idea how I got to this point. I restarted Thunderbird a few days ago, and this is all that appears. When I click on any of the top toolbar drop down menu items: New Message, Help, etc., nothing happens.

When I look at the Get Info for Thunderbird, it looks like they/Mozilla made a change on 3/24, but I don't know if that's related or not.

Did you try my second suggestion?

command+1 may work too.

Use the keyboard short cut ⌘ + 1 to open the Mail tab with the accounts and folders.

Thanks for both of your responses - I appreciate your time. I tried both: Control + 1, and ⌘ + 1 and nothing changes on my screen. No other windows open. Nothing. Is there anything else I should be clicking or holding down when I try those two options? The screen feels stuck in this Chat option (which I've never used before.)

Thanks.

Did you try Thunderbird's "troubleshoot mode"? https://mzl.la/3AbU5jz Hold the Alt key when launching TB...

The Troubleshooting Mode worked! I restarted Thunderbird while holding down Option, and my email was there and still there when I turned off Troubleshooting Mode. Whew - what a relief. Thank you!!!

This thread helped me as well! I had the same issue. Now everything is back! Thanks so much!