Hi Oscar,
are you using multiple hosts?
If yes, check the /etc/libvirt/libvirtd.conf in the host_uuid = part. If they are the same on the Hosts, the problem could be located there. I was facing this issue in the past and solved it with the following sed in my installation routine.
Suitable for Debian 8.7.1 you will need the uuid-runtime
sed -i 's|#host_uuid = "00000000-0000-0000-0000-000000000000"|host_uuid = \"'$(uuidgen)'\"|g' /etc/libvirt/libvirtd.conf
Pecadis