What is stage 3? And what is the error message? Info on stages 1 and 2 may also prove useful. Thank you.

Hi David, Thanks for responding. This is the process I went through:

First step: Clicking 'Import Tool' : 'Import from another Thunderbird installation' is chosen

Second step: 'Import from a Thunderbird profile' (I chose 'Mozilla Thunderbird' Folder from'Program Files'. Result: list ticked for Accounts and Settings, Address Book, Calendars and Mail Messages. (Address Book and Calendar are already fine. So, I unticked those)

Third step: 'Import from a Thunderbird profile' - Accounts and Settings and Mail Messages are ticked. When clicking 'Start Import' -> Error message in red: Import failed unexpectedly, more information may be avaiIable in the Error Console. (I don't know what that means)

Fingers crossed, Ulrike

Here's my suggestion: locate the profile folder, not the application folder. If your old computer was windows the profile would be on c:\users\<yourid>\appdata\roaming\thunderbird\profiles\<profilename>

Thank you, David, that was very convincing.

Particularly so, when I found the Thunderbird Profiles folder on my PC, but not on the new Laptop. I copied the whole missing 'Windows users' package (folder) onto an external drive and from there onto the laptop.

Sadly, without success in getting Thunderbird in shape. The Error Message is still the same. Puzzling is that addresses and calendars are just fine.

Could the problem start deeper? I get my emails on outlook 365 and have them transferred to Thunderbird via owl ...?

I haven't had experience in moving Exchange accounts. Since that is an online account, you may do best by setting up fresh on the new PC. ANOTHER OPTION: If the old PC is still functioning,, and if you left the profile in its default location, you can do this: - exit thunderbird on both PCs - copy c:\users\<yourid>\appdata\roaming\thunderbird to a USB stick and from there to your new PC. This willcause some overwrites, but that's okay. - start TB on new pc and everything should be there (assuming you have already installed Owl addon).

Thank you so much, David!

You helped me more than you could have expected. I had my new laptop changed from Windows 11 to Windows 10. The technician also used my backup from the PC to populate the laptop exactly like the PC. That may have caused problems that he was not aware of. Because, when I looked at the Thunderbird program, there was a lot missing. So, the transfer had only apparently worked.

The final proof was when your last instructions did not work. So, I shall have to return to the laptop repair hut. All this happening now is so much better than when life gets busy again.

Sorry to have presented you with an unsolvable problem. But thank you for helping me, Ulrike