Dear oVirt team, We have 3 Hosts HA Cluster with SHE engine. Storage is NetApp. Recently we have executed an upgrade from 4.2.8 to 4.3.2. Since then we are seeing strange behavior when trying to put Hosts to Maintenance or manually Migrate VMs between Hosts. The most repeated WARN/ERROR I am observing is following: The UI is constantly throwing an exception when trying to put HA host to maintenance or increase the SPM level. The repeated log line from engine.log I see, with regards or failing to migrate all hosts is: 2019-04-18 13:05:30,760Z WARN [org.ovirt.engine.core.bll.MigrateVmCommand] (EE-ManagedThreadFactory-engineScheduled-Thread-83) [63d33dd1] Validation of action 'MigrateVm' failed for user SYSTEM. Reasons: VAR__ACTION__MIGRATE,VAR__TYPE__VM,SCHEDULING_ALL_HOSTS_FILTERED_OUT,VAR__FILTERTYPE__INTERNAL,$hostName ovirt-staging-hv-02,$filterName Memory,$availableMem 3824,VAR__DETAIL__NOT_ENOUGH_MEMORY,SCHEDULING_HOST_FILTERED_REASON_WITH_DETAIL,VAR__FILTERTYPE__INTERNAL,$hostName ovirt-staging-hv-01,$filterName Memory,$availableMem 0,VAR__DETAIL__NOT_ENOUGH_MEMORY,SCHEDULING_HOST_FILTERED_REASON_WITH_DETAIL,SCHEDULING_ALL_HOSTS_FILTERED_OUT,VAR__FILTERTYPE__INTERNAL,$hostName ovirt-staging-hv-02,$filterName Memory,$availableMem 3824,VAR__DETAIL__NOT_ENOUGH_MEMORY,SCHEDULING_HOST_FILTERED_REASON_WITH_DETAIL,VAR__FILTERTYPE__INTERNAL,$hostName ovirt-staging-hv-01,$filterName Memory,$availableMem 0,VAR__DETAIL__NOT_ENOUGH_MEMORY,SCHEDULING_HOST_FILTERED_REASON_WITH_DETAIL But there is more than enough. Also from UI.log: 2019-04-18 14:05:09,007Z ERROR [org.ovirt.engine.ui.frontend.server.gwt.OvirtRemoteLoggingService] (default task-114) [] Permutation name: 0D2DB7A91B469CC36C64386E5632FAC5 2019-04-18 14:05:09,007Z ERROR [org.ovirt.engine.ui.frontend.server.gwt.OvirtRemoteLoggingService] (default task-114) [] Uncaught exception: com.google.gwt.event.shared.Umbrell aException: Exception caught: (TypeError) : oab(...) is null at java.lang.Throwable.Throwable(Throwable.java:70) [rt.jar:1.8.0_201] at java.lang.RuntimeException.RuntimeException(RuntimeException.java:32) [rt.jar:1.8.0_201] at com.google.web.bindery.event.shared.UmbrellaException.UmbrellaException(UmbrellaException.java:64) [gwt-servlet.jar:] at com.google.gwt.event.shared.UmbrellaException.UmbrellaException(UmbrellaException.java:25) [gwt-servlet.jar:] at com.google.gwt.event.shared.HandlerManager.$fireEvent(HandlerManager.java:117) [gwt-servlet.jar:] at com.google.gwt.user.client.ui.Widget.$fireEvent(Widget.java:127) [gwt-servlet.jar:] at com.google.gwt.user.client.ui.Widget.fireEvent(Widget.java:127) [gwt-servlet.jar:] at com.google.gwt.event.dom.client.DomEvent.fireNativeEvent(DomEvent.java:110) [gwt-servlet.jar:] at com.google.gwt.user.client.ui.Widget.$onBrowserEvent(Widget.java:163) [gwt-servlet.jar:] at com.google.gwt.user.client.ui.Widget.onBrowserEvent(Widget.java:163) [gwt-servlet.jar:] at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1415) [gwt-servlet.jar:] at com.google.gwt.user.client.impl.DOMImplStandard.dispatchEvent(DOMImplStandard.java:312) [gwt-servlet.jar:] at com.google.gwt.core.client.impl.Impl.apply(Impl.java:236) [gwt-servlet.jar:] at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:275) [gwt-servlet.jar:] at Unknown.Su/<(https://ovirt-staging-engine.avinity.tv/ovirt-engine/webadmin/?locale=en_US#dataCenters-clusters;name=Hilversum-DataCenter line 9 > scriptElement) at Unknown.anonymous(Unknown) Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError) : oab(...) is null at org.ovirt.engine.ui.uicommonweb.models.clusters.ClusterGuideModel.$onAddHost(ClusterGuideModel.java:533) at org.ovirt.engine.ui.uicommonweb.models.clusters.ClusterGuideModel.executeCommand(ClusterGuideModel.java:617) at org.ovirt.engine.ui.uicommonweb.UICommand.$execute(UICommand.java:163) at org.ovirt.engine.ui.common.presenter.AbstractModelBoundPopupPresenterWidget.$lambda$4(AbstractModelBoundPopupPresenterWidget.java:306) at org.ovirt.engine.ui.common.presenter.AbstractModelBoundPopupPresenterWidget$lambda$4$Type.onClick(AbstractModelBoundPopupPresenterWidget.java:306) at com.google.gwt.event.dom.client.ClickEvent.dispatch(ClickEvent.java:55) [gwt-servlet.jar:] at com.google.gwt.event.shared.GwtEvent.dispatch(GwtEvent.java:76) [gwt-servlet.jar:] at com.google.web.bindery.event.shared.SimpleEventBus.$doFire(SimpleEventBus.java:173) [gwt-servlet.jar:] ... 12 more Can you give me some advice on how to proceed? This started happening since upgrade. Kindly awaiting your reply, Marko Vrgotic