On 13.10.2016 02:55, mordenkainen wrote: Sigh. I wish libxml2 would report more sane error messages. But if we stretch it enough it can make sense. Just a little. Basically, this error message says, the problem is with sysinfo element. So opening up our RNG schema (docs/schemas/domaincommon.rng) you can search for conditions we put onto the element: <define name="sysinfo"> <element name="sysinfo"> <attribute name="type"> <value>smbios</value> </attribute> ... </element> </define> So, the element <sysinfo/> MUST have attribute named 'type' with value 'smbios'. Therefore if I fix your small XML: <domain type='kvm'> <name>example</name> <sysinfo type='smbios'> </sysinfo> </domain> it validates just fine. Michal