Permission denied: '/var/lib/YaST2/install.inf'

Impossible to create new machine, virt-manager throws me this error:

Permission denied: '/var/lib/YaST2/install.inf'

File in question is own by root with 600 permissions. Does this file needs to be user “qemu” readable (which would make sense)? And if yes, then something went wrong after one of many (tumbleweed) updates and ownership and/or permissions of this file got changed.
All existing machines, on the other hand, can be started and operating as usual.
From cli virt-install gives me following error:

ERROR    unsupported configuration: unknown driver format value 'block'
Domain installation does not appear to have been successful.

First i thought driver? block? what’s that? does it has to do with cdrom parameter and the fact that i was trying to boot from livecd?, so i added “livecd” parameter to virt-install command and installation started…well it’s not, it seamed at first that it did not :(.
Another issue i came across just right now - if i connect iso to existing machine and then try to “disconnect” it i get another “block” related error:

Error changing VM configuration: unsupported configuration: unknown driver format value 'block'

Any ideas where to start digging?

EDIT: i’m running 13.1 Tumbleweed with kernel 3.13.6-20.g0509ce5-desktop and libvirt 1.1.2-2.18.3

ok… i have reinstalled (pattern) kvm_server and guess what… now everything works. But before i mark the thread as “solved” i’d like to hear from knowledgeable people here what would/could be reason for this.