Check your security certificates

I just believe I noticed that Trisquel 5.5 comes with a revoked root certificate. It's the DigiNotar / Staat der Nederlanden root certificate.

Here's explanation of the problem http://en.wikipedia.org/wiki/Diginotar
And here's how to remove the DigiNotar certificate, the same method applies to Staat... just scroll a bit down http://support.mozilla.org/en-US/kb/deleting-diginotar-ca-cert

I filed a bug as well https://trisquel.info/en/issues/5534