Failed to Download Repository Information

I have a Libiquity Taurinus x200. It's running Trisquel 8 Flidas I think. And now when it tries to update I get the error message in the title of this post.

How can I get my computer to update again?

Also I get this long message when I try to reload the Synaptic Package Manager:

(Could not download all repository indexes

The repository may no longer be available or could not be contacted because of network problems. If available an older version of the failed index will be used. Otherwise the repository will be ignored. Check your network connection and ensure the repository address in the preferences is correct.

The repository 'https://archive.trisquel.info/trisquel flidas Release' does not have a Release file.Data from such a repository can't be authenticated and is therefore potentially dangerous to use.See apt-secure(8) manpage for repository creation and user configuration details.The repository 'https://archive.trisquel.info/trisquel flidas-security Release' does not have a Release file.Data from such a repository can't be authenticated and is therefore potentially dangerous to use.See apt-secure(8) manpage for repository creation and user configuration details.The repository 'https://archive.trisquel.info/trisquel flidas-updates Release' does not have a Release file.Data from such a repository can't be authenticated and is therefore potentially dangerous to use.See apt-secure(8) manpage for repository creation and user configuration details.Failed to fetch https://archive.trisquel.info/trisquel/dists/flidas/main/source/Sources server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: noneFailed to fetch https://archive.trisquel.info/trisquel/dists/flidas-security/main/source/Sources server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: noneFailed to fetch https://archive.trisquel.info/trisquel/dists/flidas-updates/main/source/Sources server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: noneSome index files failed to download. They have been ignored, or old ones used instead.)