So for a while I've been getting “An error occurred while trying to find updates for xxx” when looking for Thunderbird extension updates. A bit of a Google has shown me the fix, so I thought I'd share.
First up, make sure you have the issue I saw: open TB's preferences window, and go to Advanced/General and click ‘Config Editor’. In this dialogue, type “logging” in the filter then double click the ‘false’ next to ‘extensions.logging.enabled’ to turn it on. Remember this, you'll want to turn it back off afterwards!
Now open Tools/Error Console and clear whatever's there. Then right-click on one of the failed extensions in the extensions list (Tools/Add-ons) and try to find an update. You have this specific problem if you get an error like:
RDFItemUpdater::onXMLLoad: cert issuer is not built-in
OK, so now you need to open the prefs. window again and go to Advanced/Certificates and ‘View Certificates’ (you can set that logging setting back to false now, by the way). Go to the ‘Authorities’ tab, & scroll down to find these:
GlobalSign Partners CA
GlobalSign Root CA
GlobaSign Primary Class 1 CA
GlobaSign Primary Class 2 CA
GlobaSign Primary Class 3 CA
You need to delete the ones that are tagged as “Software Security Device” but NOT the ones that are “Builtin Object Token”. That should now let you check for updates correctly!