[ovirt-users] ova conversion errors: where to search?

Hello, testing some VMware ova imports. In a test that I'm doing I get failure in conversion; in engine.log 2017-02-17 17:39:02,992+01 INFO [org.ovirt.engine.core.bll.exportimport.ConvertVmCallback] (DefaultQuartzScheduler4) [59adde47] Conversion of VM from external environment failed: Job u'cdb31877-3ebb-400d-88da-1f645b1261ae' process failed exit-code: 1 where to find more details regarding reasons for failure? Other files on engine or should I see at host side? In case I have to import a windows VM ova, which iso should I attach near the "Attach VirtIO-Drivers" checkbox? Any "official" iso? I downloaded oVirt-toolsSetup-4.1-3.fc24.iso but I don't know if it is the right iso for this. Thanks, Gianluca