[knot-dns-users] Knot Ubuntu update

Hi, I did a "apt-get upgrade" on my Knot node. The package update fails with "Failed to initialize default key store (unknown error -13)." Can anyone tell me what that means? root@localhost:~# knotd --version knotd (Knot DNS), version 2.1.0 root@localhost:~# ps aux | grep knot knot 30048 0.0 0.6 1245236 6400 ? Ssl 16:08 0:00 /usr/sbin/knotd -d -c /etc/knot/knot.conf root@localhost:~# /etc/init.d/knot restart * Restarting Knot DNS server knotd [ OK ] root@localhost:~# ps aux | grep knot knot 30115 0.0 0.6 1245224 6200 ? Ssl 16:09 0:00 /usr/sbin/knotd -d -c /etc/knot/knot.conf root@localhost:~# apt-get upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Setting up knot (2.1.0-2+trusty+2) ... * Starting Knot DNS server knotd [ OK ] Failed to initialize default key store (unknown error -13). dpkg: error processing package knot (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: knot E: Sub-process /usr/bin/dpkg returned an error code (1) root@localhost:~# ps aux | grep knot knot 30115 0.0 0.6 1245236 6360 ? Ssl 16:09 0:00 /usr/sbin/knotd -d -c /etc/knot/knot.conf Kind regards, Volker