LE: Could not verify domain

Hi I thought there was already a report for this but I didn't find it...

Somehow suddenly (sinde latest ispc updates) my Server isn't able to verify domains for LE anymore. If I bypass the check (modifying the if clause to always be true) the issuance of certificates works as expected so this is an issue within LE only.

root@web1:~# /usr/local/ispconfig/server/server.sh


16.07.2017-20:39 - WARNING - Could not verify domain clanpartner.de, so excluding it from letsencrypt request.

16.07.2017-20:40 - WARNING - Could not verify domain www.clanpartner.de, so excluding it from letsencrypt request.
16.07.2017-20:40 - WARNING - Let's Encrypt SSL Cert for: clanpartner.de could not be issued.
finished.
root@web1:~#