I think I see a solution, but I first need to confirm a few items. You have three profiles and I don't know why. What is the purpose of the 'Local Folders' and 'From WLM'? My assumption is that you wanted the local folders to be within the 'default' profile. Please explain and then I'll present my proposal.

'Local folders' is, I believe, determined by TB itself and was added automatically after the reinstallation of TB. When I look at my backup, that folder in question was not there, but TB added it himself, I can assume. My TB copy has only two folders under Profiles (with which everything still worked): 1. a *.default folder 2. an 'From WLM' folder

Everything in that folder 'Uit WLM' is a collection of subfolders with older mails then transferred/exported from the previous laptop and that was named 'Uit WLM'. Never dared to change that and saw that folder under 'Local folders'. So that name is absolutely unimportant to me: it's the subfolders and the series of mails in each of those folders that I'd like to keep. So, yes, that those local folders would be within my default profile is fine and certainly not a problem. Then why he disappeared in the past few days wiping that separate alias account of my wife remains a mystery: everything ever came together in TB with my own alias; all others were added later

Okay, here is my suggestion. FIRST, please copy the profiles folder elsewhere in case my suggestion encounters problems. - start TB in the default profile - highlight local folders and right-click and create dummy folders for each of the sub folders with the SBD suffix (but do NOT include the suffix). For example, create folders called Auto en logins, CM, Energie, and the rest. Spelling must be exact match and same case, whether upper or lower. If spelling doesn't match, it won't work. - once you're done, exit TB (very important) - Now, copy those folders from where they are now to be under the Local Folders of the default profile. If done right, you will be prompted to overwrite files there. Click OK. - Now, Restart TB. If all went well, you should be able to click those folders and see their content open. - Once everything is working okay, you can delete the unneeded profiles. Let me know of problems. I have tested this, but as I am not seeing exactly what you are, my instructions may be wrong.

Thanks and Good morning, David. We are clearly on a different continent with big time differences... Tried to carry out your method but it already went wrong as soon as I tried to create the 1st dummy folder without extension in 'Local folders': Got an error message with content: "A folder with that name already exists. Enter a different name in". So, even though 'Local Folders' doesn't show anything, they should still be there? (see also screenshot).

In the meantime, continued 'experimenting' by trying to open various folders in 'Local Folders' ('From WLM' ; 'From WLM.sbd'; 'A - Samsung ... ' and others). Every time I get the error message that my own existing profile does not exist (??) and ... a new profile folder is added every time (which I then also delete every time): see screenshots

Are we talking about the same thing, David? All previous searches via explorer went via 'Roaming': => C:\Users\User\AppData\Roaming\Thunderbird\Profiles

However: there also appears to exist on my laptop under local: => C:\Users\User\AppData\Local\Thunderbird\Profiles in which, among other things, all profiles folders that I thought I had deleted !!

Screenshots added

This information may not be relevant but my limited knowledge does not allow you to judge it

The reason you are receiving error message that the file already exists is because the files are there. The screen shots you showed never showed local folders within the default profile. I have to rely on you. For my approach to work, you need to remove all folders from the default profile Local Folder folder. From earlier screen shots, it appears that you have those files in other places. If not, move the folders to a new place that you can access later.

Once you have all folders removed from the default\mail\Local Folders you can repeat the steps I gave earlier. That is, from within TB, create dummy folders in the Local Folders. Then copy the ones you moved back, overlaying the dummy folders.

And, I do not understand what you are doing that causes new profiles to be created. When I do these steps, and just these steps, there is no new profile. Anyway, let me know how it goes. When it finally works, you may find that you have several extra copies. Also, don't let the appdata\local\thunderbird files confuse you. when all is done, they can be deleted.

David. Went wrong. Sorry I retrieved 2 older profile versions from February 27 (= before the major changes) and even one from half last year. Since, to my knowledge, no emails or new folders were created recently, this should be an intact version. Probably best to reset everything? Only: do I now do well to remove everything, including the program from TB (but then really everything: but how?) and reinstall everything, or is it sufficient to remove the faulty profile and replace it with the previously intact one where I then have to redo all adjustments. It is clear that a lot of trouble was accumulated by importing it through that WLM folder at the time. Maybe it would be better then, if it works again, to put those subdirectories directly in local directories and eliminate that WLM state??

Dear David. In the meantime my profile and 'From WLM' folder have been deleted and have to revert to an old version from mid-2021. There I did indeed find the local files visible. Something must have gone wrong in the intervening time. So luckily that worked and thanks to your clarifications. To my great surprise, TB - however erased EVERYTHING from that profile (!!) - remembered and applied my most recent changes. Even after I completely deleted that same (defective) profile! Strange but luckily no problem. Only my - previously solved by you - problem regarding transferring my google contacts I will have to reinstall. Thanks for all the help and effort you made to solve my problems

So, is everything fixed?

Yes, David, looks like everything will work now. I may come across other obstacles in the near future, but now I know the way where I can actually be helped.

Thank you very much for your time and your expertise: only I would not have managed this and I would have continued to struggle with the proximus webmail version.

I am so pleased for you. A suggestion: copy the entire folder of c:\yourID\appdata\roaming\thunderbird to somewhere else on your PC. That doesn't protect you if the disk crashes, but if a future update of Thunderbird causes any disruption, you would have the backup. Regards and best wishes. david