System Analysis certificate not vaild after running letsencrypt

Ungültiges Zertifikat ‘/etc/univention/letsencrypt/signed_chain.crt’ gefunden:
error /etc/univention/letsencrypt/signed_chain.crt: verification failed
but
List all certificates (including revoked and expired certificates)
01 ucs-xxxx-web.mydomain.de (V)
02 ucs-sso.mydomain.de (V)
03 dudle-yyyyyyyy.mydomain.de (V)
and at starting ucs portal : still warning https not safe, not valid certificate.

What is wrong? at log letsencrypt everything is ok.