“invalid security certificate” warning makes entire Thunderbird unusuable and recoverable

Version: 8.0+build1-0ubuntu0.11.10.1 (64bit)

Steps to reproduce:

1. Install add on.
2. Set up calendar by pointing the add-on to an Exchange URL that uses a certificate chain with an untrusted root certificate.

Expected: I’d be able to accept the certificate (manual override). Or at least be able to uninstall the add-on and not use it at all.

Actual: A certificate warning appears that I can’t cancel out of, rendering Thunderbird completely unusable.

The exact wording of the warning is as follows:

Secure Connection Failed

mail.example.com:443 uses an invalid security certificate.

The certificate is not trusted because no issuer chain was provided.

(Error code: sec_error_unknown_issuer)

The only choices are “View Certificate” and “Cancel”. Pressing “Cancel” brings up the same popup again immediately.

Ending Thunderbird with SIGTERM, and re-opening, results in the popup immediately appearing again, which prevents me from uninstalling the add-on.

Note: Thunderbird is also using 100% CPU at this time.

You’ll forgive me if I haven’t provided more detail, as I can no longer access anything in Thunderbird.

Simon Schubert suggests this article as an answer to your question:
FAQ #1290: “How to accept an exception for an “invalid security certificate”?".

Hilarious. What’s the point of having a bug tracker if no one is going to actually read the bug reports?

The actual workaround for the bug is to open Thunderbird in safe mode (http://kb.mozillazine.org/Safe_Mode) and uninstall the add-on.

On second thought, maybe I’m being too hard on the developers, as my bug report probably wasn’t very clear to a casual glance. I just find it extremely annoying when I try a new add-on and it breaks my entire mail client until I figure out how to get it usable again.