“new folder” in my inbox is gone after restart

Am having an issue with creating a “new folder” in my inbox. I create the folder, shut Thunderbird down, re-open it and the folder is not there. Did this three times, same result. A

lso, having an issue with tagging. I will click on an email, right click, and nothing happens. I have to click on another email, click the original email, then I can tag it. I suspect a corrupted profile but, not sure. Any ideas?