A quick blog post because I ran into the issue of Firefox not connecting to certain HTTPS sites, and I could not find a solution. Well, the only offered solution was “clear your profile” but I don’t want to do that. It takes a lot of effort to get back up running, even with Firefox sync.
I was for a longer time not able to visit the website from the tax authority of my country (Belastingdienst), but suddenly I could not visit Twitter as well.
- For the HTTPS connection to Belastingdienst I ran into
- For the HTTPS connection to Twitter I had simply “connection failed” without any details
Check your SSL/TLS settings
First of all, start a Firefox instance with a clean profile. In your current instance and clean instance, compare the results of the
about:config pages. Search on “https”, “ssl”, and “tls”. Check if you have any keys that deviate from the defaults, shown in bold, and reset them.
Clear your local caches
%localappdata%\mozilla\firefox. You can find a folder there called “Profiles”. You can delete this. It only contains cached data.
After deleting everything should be working again.