Comment # 3 on bug 905653 from Martin Pluskal

Please provide yast logs (see
https://en.opensuse.org/openSUSE:Report_a_YaST_bug), also my guess is that you
are recieving this error becaus /dev/sda is usb flash from  which you are
running installation. You can avoid it by selecting different hard drive (the
one which you actually want to use).

Also please do not change priority of issue, it is meant to be set by
project/release managers.