Some clarification may help. You mention copying 'the whole thunderbird folder.' Was that just the exe, or did it include the profile? Where was the profile stored? On the default drive c in the appdata\roaming\thunderbird folder? I ask that because when thunderbird starts, it immediately attempts to open the profiles.ini (text file) in the appdata\roaming\thunderbird folder to retrieve the name and location of the default profile. If thunderbird is stating it can't find the profile, what that means is that it either can't find the profiles.ini file or the folder being pointed to has been moved. If thunderbird is finding the profiles.ini, it's easy to edit the file to point to the desired profile. These comments of mine may not 'solve' your issue, but I hope they help you investigate your issue.

Thank you for the response!

I have Thunderbird on the D: drive, that was where the Thunderbird was loaded on to. That is the folder I moved (on the D: drive) into the new folder (on same D: drive).

Everything was originally loaded up "as is", and never altered. Which leads to your 2nd question, the profile was in it's default location as you mentioned c: drive in the appdata\roaming\thunderbird folder, as I have never altered that in any way. I can see my original ported file there, dated to the day I moved it (in 2023).

I agree with you it cannot find the profiles.ini that I need it to. The question for me is, is the profile.ini (the original one I ported over to my new computer), is that the profile that Thunderbird updates that folder over and over, but keeps the modified date as the original port over date? Or should there be a profile with a more current date, like as of yesterday when I was using Thunderbird before I moved the folder, I'm thinking it would have a 7/22/2025 date.

The current app data profile folder still has that original port date profile; but, I was thinking there should be a more recent profile date (like current day). There was a profile in there from yesterday (I know this because of the time created), but it's the one that was made when I moved the folder, and the one Thunderbird used to start itself, which was the set up menu for un/passwrd/setup. So I inferred that wasn't right. I know I need the profile I was using before that 6 pm profile.

Nothing else has been touched (other than me deleting that one profile that was 10:30 pm yesterday, which I know is junk because I got the set up menu again). The only thing I did was moved that main Thunderbird folder, to a new folder, on the same drive.

No changes of profiles in the app data section were touched/moved. This is what is so puzzling to me. If the original ported profile file (from 2023) is the correct one, that will get me back to where I was yesterday before I moved the folder, then I'm gold.

I just don't want to fiddle with it anymore before I'm sure that's going to solve the issue.

I hope that makes sense; and again, I really appreciate you looking at this!

• • RESLOUTION UPDATE**

I figured it out, well, I never did figure out where the profile ini file went, which seems to be the whole issue; however, I did the most high tech thing you can do, I moved the entire Thunderbird folder out of the D: programs folder back to the D: main folder (Thunderbird is its own folder). Once back to it's original download spot, it was happy again, pulled up no problems; and all my saved emails were there, thank Odin (yes I immediately backed up my profile folder).

Thank you david for taking a look at this, I really do appreciate that!

Hope this helps someone in the future.