upgrading 57a to 65: unhandled exception in mailinabox run when upgrading nextcloud about mailinabox HOT 2 OPEN

As an aside, this conversation probably belongs in the mailinabox.email user forum so others can learn from it, but here goes.

I'm not sure why this happened, based on the info you've provided:
ln: failed to create symbolic link '/home/user-data/ssl/ssl_certificate.pem': File exists

But I can tell you that deleting the .../ssl/ directory after that is incorrect and most certainly caused the "unhandled exception" issue. Basically, the duplicity backup contains your SSL certificates, which is why the instructions are to delete the ssl directory, then restore the backup. You have deleted the directory, restored the backup, then deleted the directory again. So, for starters, you need to get that directory re-populated from the backup. I would advise (1) restoring the backup in a separate location (so what is in there is available), (2) make sure the ssl directory is now empty, then (3) restore the ssl directory (only the ssl directory) from the backup you opened in (1). If you copy it by hand make sure everything in /home/user-data/ssl/ is identical (permissions, ownerships, links, etc) to what is in the backup directory.

Once you're done with that, try running sudo mailinabox again. Also, you didn't post it above, but you need to use sudo (or be root) when you run the duplicity restore.

from mailinabox.

I was aware of the fact that re-running removal of ssl folder isn't in compliance with the upgrading instructions. However, I was expecting duplicity to properly restore the folder in the first place and somehow this didn't seem to happen either. There are no extra steps I might have forgotten to mention here. Hence, I'm not sure if manually copying ssl folder and restoring its permissions will make any difference for that's what I'd expect duplicity to do, too. But I'll give it a try just to be sure ...

And FWIW all commands have been run as root. I see the slight benefit of not working as root by default, but quite often (not just with regards to MIAB in particular) I have to log in as non-root just so that I can use sudo which isn't mitigating any security risks that much and still requires me to always proceed with great care.

from mailinabox.