Quassel IRC

Im using Letsencrypt certificates with secp384r1, but when i give quassel-core the certificates are ignored by quassel-core.
This is from my logs after i combined the private an public key, i made this to be sure that the symlinks used by dehydrated arent the cause.

Jul 15 01:09:20 server quasselcore[3684]: 2020-07-15 01:09:20 [Warn ] SslServer: Failed to open certificate file /var/lib/dehydrated/certs/server/fullkey.pem error: 5
Jul 15 01:09:20 server quasselcore[3684]: 2020-07-15 01:09:20 [Warn ] SslServer: Unable to set certificate file
Jul 15 01:09:20 server quasselcore[3684]:            Quassel Core will still work, but cannot provide SSL for client connections.
Jul 15 01:09:20 server quasselcore[3684]:            Please see https://quassel-irc.org/faq/cert to learn how to enable SSL support.
Jul 15 01:09:20 server quasselcore[3684]: 2020-07-15 01:09:20 [Warn ] SslServer: Failed to open certificate file /var/lib/dehydrated/certs/server/fullkey.pem error: 5

Im using debian buster with backports enabled.
I have checked the rights and the certificate is also used by nginx without problems.

This is my commandline that is used:

/usr/bin/quasselcore --config-from-environment --configdir=/var/lib/quassel/ --loglevel=Debug --port=4242 --listen=0.0.0.0,:: --ssl-cert /var/lib/dehydrated/certs/server/fullkey.pem

with an RSA-certificate it works without problems.