Comment 6 for bug 1324848

Also, just to update people who might not have followed the conversation on IRC. The issue is that the cache database is missing data (specifically https). Once that happens, the webapps break is 100% reproducible. What's unclear is how the cache database ends up in that state. As a work around you can delete the cache database and it will get reconstructed.

rm ~/.cache/url-dispatcher/urls-1.db
<restart your session>