I found the following LOG entrie
What is this EDIT_ADMIN_VM_PROPERTIES ?
2015-11-20 16:42:10,888 DEBUG [org.ovirt.engine.core.bll.AddVmCommand] (default task-160) [2f0eb905] Checking whether user 'acc9ced5-a764-4d60-84d7-db4b4a498a18' or one of the groups he is member of, have the following permissions: ID: a303bbca-af20-4de5-9eff-01c52d3bf615 Type: VdsGroupsAction group CREATE_VM with role type USER, ID: 00000000-0000-0000-0000-000000000000 Type: VmTemplateAction group CREATE_VM with role type USER, ID: a303bbca-af20-4de5-9eff-01c52d3bf615 Type: VdsGroupsAction group EDIT_ADMIN_VM_PROPERTIES with role type ADMIN
2015-11-20 16:42:10,890 DEBUG [org.ovirt.engine.core.bll.AddVmCommand] (default task-160) [2f0eb905] Found permission '129c57bb-df56-4529-93d9-52db0265263f' for user when running 'AddVm', on 'Cluster' with id 'a303bbca-af20-4de5-9eff-01c52d3bf615'
2015-11-20 16:42:10,893 DEBUG [org.ovirt.engine.core.bll.AddVmCommand] (default task-160) [2f0eb905] Found permission '00000004-0004-0004-0004-000000000355' for user when running 'AddVm', on 'Template' with id '00000000-0000-0000-0000-000000000000'
2015-11-20 16:42:10,894 DEBUG [org.ovirt.engine.core.bll.AddVmCommand] (default task-160) [2f0eb905] No permission found for user when running action 'AddVm', on object 'Cluster' for action group 'EDIT_ADMIN_VM_PROPERTIES' with id 'a303bbca-af20-4de5-9eff-01c52d3bf615'.
2015-11-20 16:42:10,894 WARN [org.ovirt.engine.core.bll.AddVmCommand] (default task-160) [2f0eb905] CanDoAction of action 'AddVm' failed for user vincent.engel@hitmeister.de@hitmeister.de. Reasons: VAR__ACTION__ADD,VAR__TYPE__VM,USER_NOT_AUTHORIZED_TO_PERFORM_ACTION