TLS Errors on Some Websites but Not All

The Smoothwall Filter generates replacement certificates for websites on the fly and caches them for re-use. It might be that a site certificate has been replaced and the cached certificate that the Smoothwall created is causing this error.

Procedure

1. Clear the cache by going to Guardian menu under the HTTPS inspection submenu and click Settings.
2. Click Clear and restart, next to the Cached certificates header.
3. Close the web page and reopen to check if that has fixed the issue.