"No matching secret key" - (secret key not found)

[HeRo]

Hi

For almost a year I have used Enigmail for signing, encrypting, and decrypting emails in Thunderbird under Windows 7. Now I have copied my whole Thunderbird profile to a new laptop running Ubuntu (first 17.10, now 18.04 LTS). But I have not yet been able to sign or decrypt or even save draft emails in Thunderbird v.52.7.0 (64-bit).
When I try to decrypt an email I get this error:
"Error - no matching secret key found to decrypt message"
When I save a draft email, close it, and try to re-open it, the message content is empty. (The headers are intact.)
When I try to send a mail which I want to sign, I get this message:
Enigmail Alert: "You do not seem to have the secret key for XX on your keyring; you cannot use the key for signing."

I would VERY much appreciate some help, thank you.

Best regards,
Henrik R.

[Patrick Brunschwig]

Your keys are not in the Thunderbird profile. GnuPG stores the keys in %USERPROFILE%\AppData\Roaming\gnupg on Windows and in ~/.gnupg on Linux. You need to copy the complete directory including subfolders to your new laptop.

[HeRo]

Great! Thank you! Now everything works perfectly.