I have just installed a letsencrypt certificate via the server certificate module on my Nethserver 7 (final version).
It seems that it worked fine, i.e. the new certificate is shown in the list of certificates and no errors are shown in the log file. I set the certificate to default.
However, when I browse to my website that I host on Nethserver, firefox shows an error message that the SSL certificate is not secure and gives the following error code to me: SSL_ERROR_WEAK_SERVER_EPHEMERAL_DH_KEY
could it be that the module uses a prime that is not large enough (for the Diffie-Hellman algorithm)? or does Nethserver use another algorithm? And do you have any idea how to fix that problem?