Open the profile folder. Inside you will see the prefs.js file. Was it recently created/modified, or does it still have the date as at the creation of the image backup? Can you browser/explore the image backup and extract the Roaming/Thunderbird folder only?

Open the profile folder. Inside you will see the prefs.js file. Was it recently created/modified, or does it still have the date as at the creation of the image backup? Can you browser/explore the image backup and extract the Roaming/Thunderbird folder only?

Thank you for your swift reply, Stans. I have verified that the prefs.js was modified during the problem (6 July). The external hard drive contains a backup copy with a modified date earlier than any problems (early 4 July). Replacing the entire profile in roaming AppData while the client is closed doesn't correct the problem. Also, there have been numerous prefs.js files up to prefs-11.js (1 July) at successive times, which the backup contains.

I'm questioning if the directoryTree.jsn file is corrupted (even in the backup), because I can make the contents (and subfolders) of storage folders pop into existence by creating them manually from the root local mail folder.

What should I do?

I'm questioning if the directoryTree.jsn file is corrupted (even in the backup), because I can make the contents (and subfolders) of storage folders pop into existence by creating them manually from the root local mail folder.

You probably mean the folderTree.json file? That is the one used by the folder pane. The directoryTree.json file is used by the address book. You could rename the folderTree.json file while Tbird is NOT running, then relaunch it.

You probably mean the folderTree.json file? That is the one used by the folder pane. The directoryTree.json file is used by the address book. You could rename the folderTree.json file while Tbird is NOT running, then relaunch it.

Right; folderTree.jsn. I tried to do that, but nothing changes, and even the e-mail account that I added (which is not the same as any of those I had before) remained in the profile, even after renaming folderTree.jsn. Somehow the old data stays in the roaming folder while at the same time using only the information in the profile added since the problem started.

TRy this:

• Exit Thunderbird
• Access the profile name folder.

re: numerous prefs.js files up to prefs-11.js

If any have a size of 0 (zero) then you can safely delete them. Try working through the other 'prefs' files renaming to see if one works.

• Rename 'prefs.js' (this is the one currently being used) to say a number higher than you can see eg: 'prefs-12.js'
• Rename 'prefs-2.js' to say 'prefs.js'
• Start Thunderbird.

If no joy:

• Exit Thunderbird and access profile name folder.

• Rename 'prefs.js' back to 'prefs-2.js'
• Rename 'prefs-3.js' to say 'prefs.js'
• Start Thunderbird

I think you get the idea, to see if one of the 'prefs' files is ok.

TRy this:

• Exit Thunderbird
• Access the profile name folder.

re: numerous prefs.js files up to prefs-11.js If any have a size of 0 (zero) then you can safely delete them. Try working through the other 'prefs' files renaming to see if one works.

• Rename 'prefs.js' (this is the one currently being used) to say a number higher than you can see eg: 'prefs-12.js'
• Rename 'prefs-2.js' to say 'prefs.js'
• Start Thunderbird.

If no joy:

• Exit Thunderbird and access profile name folder.

• Rename 'prefs.js' back to 'prefs-2.js'
• Rename 'prefs-3.js' to say 'prefs.js'
• Start Thunderbird

I think you get the idea, to see if one of the 'prefs' files is ok.

I tried the prefs.js method, but it doesn't seem that prefs.js contains the folder/account data. The test e-mail account and test local folder(s) remained the same even with the prefs.js changes. Also, I just now attempted to replace both the local and roaming AppData folders with an older backup from over a month ago and it still didn't fix the problem. Instead, the test account and folders just vanished. What should I try next?

Cross that! I made an error because I was in the new profile I was testing. I think it was all brought back! One moment while I verify with a clean restore.

It worked! Everything is back! Thank you so much, Stans and Toad-Hall, for all of your help!

As a note, I think that the original prefs.js was corrupted on all backup. I think the reason for that is because my backup software isn't sure how to backup that file when Thunderbird is running in the background. That doesn't make too much sense to me, since it backed up system files without a problem (except that I may have been seen as a different unique user by the system when restoring my entire hard disk). Regardless, this is a big success, so once again, thank you!

Doesn't make sense to me too, especially since copying the file in use should not pose or cause problems because any changes or lackthereof to that file after its backup do not affect the backup copy, unless your backup scheme keeps only one version/copy of the file. Backing up is a complicated process and if not implemented properly, you could end up with unusable backups. If your backup software has the option to run a program before the start of a scheduled backup, you could configure it to run a batch script that kills Thunderbird first, and another to launch Tbird after the backup. Even if your backup software doesn't have pre and post backup options to run scripts or programs, you could use the Task Scheduler to accomplish the same. Anyway, I'm glad everything worked out. You're welcome.

Doesn't make sense to me too, especially since copying the file in use should not pose or cause problems because any changes or lackthereof to that file after its backup do not affect the backup copy, unless your backup scheme keeps only one version/copy of the file. Backing up is a complicated process and if not implemented properly, you could end up with unusable backups. If your backup software has the option to run a program before the start of a scheduled backup, you could configure it to run a batch script that kills Thunderbird first, and another to launch Tbird after the backup. Even if your backup software doesn't have pre and post backup options to run scripts or programs, you could use the Task Scheduler to accomplish the same. Anyway, I'm glad everything worked out. You're welcome.

I created a simpler solution of just creating a backup copy of the prefs.js file in case I ever need to restore everything again. And if I modify the folders or add new accounts, I'll copy the file again. I use EaseUS Todo Backup, which has proven pretty useful as freeware. Windows 10 was restored fully sector-by-sector without any problems other than an easy-to-fix permissions problem with files in the root Documents and Videos folders. At the very least here, I hope this thread will help others who have lost their accounts and folders listings.

It's a good thing Tbird already makes backups of the prefs.js file.

I have the same problem. Done a windows 10reinstall and using the old method to save and restore the profile for thunderrbird. But it doesn't work. and the trick for prefs.js doesn't work. Any idea?