Enigmail plugin does not recognize anymore my private key

I am using a Debian unstable with Iceweasel (38.2.0esr-1) and the Enigmail plugin (2:1.8.2-3) from the distribution packages. I recently upgraded my system and got a new version of the gnupg2 package (2.1.7-2, previous was 2.0.28-2) and I ran into problems when trying to use my private key (encrypt, decrypt, sign messages) in Enigmail since then. The error message is: > Enigmail: Error - no matching private/secret key found to decrypt message; > click on 'Details' button for more information And, the 'Details' button was giving the following error message: Enigmail Security Info Error - no matching private/secret key found to decrypt message gpg: decryption failed: No secret key Note: The message is encrypted for the following User ID's / Keys: 0xAAAAAAAAAAAAAAAA (Surname Name gpg2 --decrypt command line, it works like a charm without any visible problem. I looked in the Debian BTS about Enigmail and found a bug with similar characteristics ([Debian Bug #794627](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=794627)) . It has not been solved because the maintainer cannot reproduce the bug. I tried several things with no success, so if you encounter this bug and find something about it, I would be pleased to know how to solve it. Any input is welcome.