I often categorize my mail in differents files and subfolders.

Do you want to say that you move messages to keep them in different folders and sub-folders in Thunderbird? So isn't what you call the file "Retraite" rather a folder somewhere in the folder pane? And "Agile Retraite" is a sub-folder of the folder "Retraite"? Did you create "Retraite" as a folder in Local Folders?

Yes I created different folders and sub-folders in order to keep my messages related to different subjets. I hence created a folder called "RETRAITE" in which I categorize my mails in different sub-folders like "Agile Retraite" (Like drawers). Both folder "RETRAITE" and sub-folders "Agile Retraite" has disapeared without any action from me. I has just disapeared.

WHERE exactly did you create the folder "Retraite"? In your Local Folders ? if you use the French Thunderbird locale they will be called "Dossiers Locaux". Or did you create "Retraite" as a sub-folder of Inbox?

A somewhat common error is accidentally dragging a folder into a neighboring folder. Expand all the neighboring folders and look for the one that is missing.

You might also check in webmail to see if the folder is where you expect it to be. If it is, but it is not showing in Thunderbird, you probably must subscribe to it again. Right click on the account name in the folder pane, select "Subscribe", and check the folder.

Or skip checking webmail and just see if the folder is available to be subscribed to.

If the folder is not inside another folder, not in webmail, and not available to be subscribed to, perhaps you deleted it accidentally. You will have to restore it from a back-up copy.

Good morning to you,

Reading your answer suggest that nothing is wrong in Thunderbird apart from me. The folder I told you had really diseappeared in front of me eyes. I am not gonna spend my days trying to explain to you what happenned. I've already been judged.

Thanks anyway,

Where did I judge you or where did I say that nothing is wrong in your Thunderbird installation? I am not Madame Soleil and I don't know what really happened, so I have to ask questions.

Go to Aide > Informations de dépannage > Dossier de profil > Ouvrir le dossier, then quit Thunderbird. Now you'll see the Thunderbird profile folder named somewhat like "xxxxxxxx.default-release" displayed in your Windows Explorer (or file manager or whatever they call it today). Do a search for a file named "Retraite" or "Agile Retraite"..... If you find one of those files please show a screen shot with its location

Another possibility already evoked by Rick: if your steprav@free.fr account is set up as an IMAP account >>> R-click on steprav@free.fr > S'abonner... which will open the list of all folders contained in this account. If you see your missing folders you can subscribe them.

Reading your answer suggest that nothing is wrong in Thunderbird apart from me. The folder I told you had really diseappeared in front of me eyes. I am not gonna spend my days trying to explain to you what happenned. I've already been judged.

I'm sorry that you feel that way, steprav. It is an unpleasant feeling.

But no one judged you. Troubleshooting involves identifying possible causes of a problem and possible solutions. I identified two possible user errors because users really do make those errors. I myself have made them and I have helped other users who have made them. The problem with subscriptions could be caused by Thunderbird. It has happened to me.

No, you did not say that the sub-folder had disappeared "in front of [your] eyes". Do you mean that while you were looking at the list of folders, that folder simply disappeared? That would be new information that would suggest other possible causes.

No one is asking you to spend days explaining what happened. But we hope that you will participate in a conversation with us so we can help you, and we hope that you will try our suggestions. Maybe they will work; maybe they will not work. If they do not work, we will try again.

If you were expecting something else when you came here, such as someone knowing exactly what is wrong with Thunderbird that caused this problem and exactly how you can recover a missing folder, your expectation was probably unrealistic. I am not aware of a problem in Thunderbird that causes folders to disappear spontaneously.

I am eager to know if that folder is inside another folder, if it is available in webmail, if you can subscribe to it, and if it can be found in the file system (Mapenzi's latest idea). That information could help us solve the problem, make us look harder for other causes, or show us that the folder cannot be recovered except from a back-up copy.

Hello,

I must apologize to you because my previous answer was quite rough. Thank you to keep trying helping me out.

You wrote : " No, you did not say that the sub-folder had disappeared "in front of [your] eyes". Do you mean that while you were looking at the list of folders, that folder simply disappeared? That would be new information that would suggest other possible causes.

I reply : Yes I did see the folder called "PROFESSIONNEL" and sub folder called "RETRAITE" disappear in front of me very eyes !

Here is the things I made :

1st : I clicked right on steprav@free.fr to create a new file named "RETRAITE" which I drag to put underneath a folder called "PROFESSIONNEL". "R" after "P".

Instead of placing itself at the right position just as a new folder would, it rewrote the whole folder "PROFESSIONNEL". I had then 2 folders called "PROFESSIONNEL" with all sub-folders underneath. I don't know where the folder called "Agile retraite" went.

2nd : After few seconds, the 2 folders (The one I had and the one which was created) disappeared.

The problem is that I've lost the previous folder called "PROFESSIONNEL" and the one "Agile Retraite" I wanted to create.

That's no very simple to explain!

I reply : Yes I did see the folder called "PROFESSIONNEL" and sub folder called "RETRAITE" disappear in front of me very eyes !

In your first message you wrote "I discovered that the subfolder "Agile Retraite' under the file called "Retraite" had diseapeared completely from thunderbird. " And now it is another folder called PROFESSIONNEL which disappeared in front of your eyes... You still did not reply to our question whether this account is a POP or an IMAP account". Anyway, I'll keep my nose out .....

Mapenzi, please keep your nose in. I have no ideas yet.

It is hard to know exactly what happened. Where was "Agile Retraite" to start with? At first, you said that it was in "Retraite". That seems inconsistent with your more recent description of the problem. Your screen image shows a "Professionel" folder. That also seems inconsistent with your more recent description, in which you seemed to say that both copies of "Professionel" disappeared. You have described "Retraite" as a sub-folder of "Professionel", but you said that you dragged it into alphabetical order after "Professionel", which would have placed it at the same level of "Professionel".

In any case, folders should not disappear spontaneously. But all I can do with this problem is ask some questions that might reveal useful information.

Why did you have to drag "Retraite" into alphabetical order. Did Thunderbird not put it in alphabetical order when you created it?

Are you using any add-ons?

Are you using anti-virus software?

Is the account a POP account or IMAP account?

Apparently, there is no possibility that the missing folders ended up inside other folders. Is that right?

If it is an IMAP account, are the missing folders visible in webmail?

When you right click on the account name and select "Subscribe", do you see the names of the missing folders in the list?

Do you access this account from other devices or e-mail clients?

One tip that might help in the future: To create sub-folders of existing folders, right click on the parent folder's name and create the sub-folder instead of creating a folder at the wrong level and dragging it to the right level.

I'm sorry if I have misunderstood something. I'm trying hard.