Hey Guido.
On Sun, 2018-04-08 at 10:36 +0200, Guido Günther wrote: > Please check the > libvirt > logs. syslog shows: $ journalctl -f | grep libvirt Apr 08 12:19:43 heisenberg libvirtd[1686]: 2018-04-08 10:19:43.236+0000: 1752: error : virFirewallApply:918 : internal error: Failed to initialize a valid firewall backend Apr 08 12:19:43 heisenberg libvirtd[1686]: 2018-04-08 10:19:43.290+0000: 2134: error : virFileReadAll:1420 : Failed to open file '/sys/class/net/virbr1-nic/operstate': No such file or directory Apr 08 12:19:43 heisenberg libvirtd[1686]: 2018-04-08 10:19:43.290+0000: 2134: error : virNetDevGetLinkInfo:2552 : unable to read: /sys/class/net/virbr1-nic/operstate: No such file or directory Apr 08 12:19:43 heisenberg libvirtd[1686]: 2018-04-08 10:19:43.355+0000: 1754: error : virFirewallApply:918 : internal error: Failed to initialize a valid firewall backend Apr 08 12:19:43 heisenberg libvirtd[1686]: 2018-04-08 10:19:43.429+0000: 2134: error : virFileReadAll:1420 : Failed to open file '/sys/class/net/virbr1-nic/operstate': No such file or directory Apr 08 12:19:43 heisenberg libvirtd[1686]: 2018-04-08 10:19:43.429+0000: 2134: error : virNetDevGetLinkInfo:2552 : unable to read: /sys/class/net/virbr1-nic/operstate: No such file or directory when trying to start the network. Do you think there'll be an update to this soon if not I simply downgrade :) Cheers, Chris.