A mess with grayed out folders, Userfolders appearing, unk why this happened

Im not sure what the heck happened about a month or so ago, and I have still not resolved it. I did check on thing that was suggested to me, but it didnt really make much of a difference. After an update at about that time, my email folders I made appeared all wacky in the sense that some folders were grayed out, but still retained subfolders (with their contents) in them. I dont know what that means or why they are grayed out. I also noticed a bunch of folders named Userfolder with a number after that. They contain many emails in each one, like they were removed from the original folder they were in. So I dont know, for most of them, what folder I had them in. Im thinking I can try and match them to the grayed folder they might belong to, but not sure on where some go. I have no idea why this happened, and I have been trying to use Thunderbird since then. Im attaching a photo of what part of my Thunderbird, folders & grayed out folders look like. I just want to know how to correct this and get things back in order. I dont know if I did something in the settings or what. Plus this was over a month ago. Ive just been using my yahoo mail account on the web.