Please post a screen shot to this topic see https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem

Here are the home panel of Thunderbird as well as the panel for Manage Folder Subscriptions. ALL of the folders in the MFS panel used to be listed under HOTMAIL on the home panel.

Shouldn't you have each folder checkbox enabled in the Subscribe window?

First off, rest assured I did not ever UNCHECK those boxes. I have no idea what that panel is for.

I have already (and again with your response) checked all of those boxes and hit subscribe then OK. Panel goes away. If I go right back to that panel nothing is checked. I really brought up that panel to prove TB does KNOW the folders exist.

It looks like another example of this problem: "I have 3 email accounts..." was recently posted.

Any correlation?

First off - yesterday, after what, a week or so, the missing folders suddenly appeared. I had logged onto TB maybe 10 times during the day then all of a sudden everything was as it should be. Didn't last long, this morning logged into TB and the problem is back.

Second thing - scanning this support forum I find a significant number of other folks with the same issue.

yup. problem not caused by Thunderbird. see https://support.mozilla.org/en-US/questions/1105490

After posting this morning I rummaged around in TB. By accident I found the option to show only subscribed folders. Since when I checked the individual folders in subscribe they immediately unchecked I thought I would give it a shot. I unchecked show only subscribed folders and things looked correct.

So far it seems to be working.