oVirt: Version 4.1.7.1-1.el7.centos

CentOS 7.4

Kernel 3.10.0-693.2.2.el7.x86_64

I'm trying to clone a snapshot to export but am getting the following errors, any suggestions ?

In web-ui:

Uncaught exception occurred. Please try reloading the page. Details: (TypeError) __gwt$exception: <skipped>: qib(...).e is null
Please have your administrator check the UI logs

ui.log:

2017-09-26 08:59:40,871+01 ERROR [org.ovirt.engine.ui.frontend.server.gwt.OvirtRemoteLoggingService] (default task-41) [] Permutation name: 7DB6BC4D2EE32C078419FA8B25F06F9C
2017-09-26 08:59:40,871+01 ERROR [org.ovirt.engine.ui.frontend.server.gwt.OvirtRemoteLoggingService] (default task-41) [] Uncaught exception: com.google.gwt.core.client.JavaScriptException: (TypeError)
__gwt$exception: <skipped>: qib(...).e is null
    at org.ovirt.engine.ui.uicommonweb.models.vms.UnitVmModel.$isHostedEngine(UnitVmModel.java:1888)
    at org.ovirt.engine.ui.common.widget.uicommon.popup.AbstractVmPopupWidget.$edit(AbstractVmPopupWidget.java:1515)
    at org.ovirt.engine.ui.common.widget.uicommon.popup.AbstractVmPopupWidget.edit(AbstractVmPopupWidget.java:1515)
    at org.ovirt.engine.ui.common.widget.uicommon.popup.AbstractVmPopupWidget.edit(AbstractVmPopupWidget.java:1515)
    at org.ovirt.engine.ui.common.widget.uicommon.popup.AbstractModeSwitchingPopupWidget.edit(AbstractModeSwitchingPopupWidget.java:78)
    at org.ovirt.engine.ui.common.view.popup.AbstractModelBoundWidgetPopupView.$edit(AbstractModelBoundWidgetPopupView.java:36)
    at org.ovirt.engine.ui.common.view.popup.AbstractModelBoundWidgetPopupView.edit(AbstractModelBoundWidgetPopupView.java:36)
    at org.ovirt.engine.ui.common.presenter.AbstractModelBoundPopupPresenterWidget.$init(AbstractModelBoundPopupPresenterWidget.java:143)
    at org.ovirt.engine.ui.common.widget.popup.AbstractVmBasedPopupPresenterWidget.$init(AbstractVmBasedPopupPresenterWidget.java:68)
    at org.ovirt.engine.ui.common.widget.popup.AbstractVmBasedPopupPresenterWidget.init(AbstractVmBasedPopupPresenterWidget.java:68)
    at org.ovirt.engine.ui.common.widget.popup.AbstractVmBasedPopupPresenterWidget.init(AbstractVmBasedPopupPresenterWidget.java:68)
    at org.ovirt.engine.ui.common.uicommon.model.ModelBoundPopupHandler.$handleWindowModelChange(ModelBoundPopupHandler.java:96)
    at org.ovirt.engine.ui.common.uicommon.model.ModelBoundPopupHandler$1.$eventRaised(ModelBoundPopupHandler.java:77)
    at org.ovirt.engine.ui.common.uicommon.model.ModelBoundPopupHandler$1.eventRaised(ModelBoundPopupHandler.java:77)
    at org.ovirt.engine.ui.uicompat.Event.$raise(Event.java:99)
    at org.ovirt.engine.ui.uicommonweb.models.Model.$onPropertyChanged(Model.java:471)
    at org.ovirt.engine.ui.uicommonweb.models.Model.onPropertyChanged(Model.java:471)
    at org.ovirt.engine.ui.uicommonweb.models.Model.$setWindow(Model.java:93)
    at org.ovirt.engine.ui.uicommonweb.models.vms.VmSnapshotListModel.$cloneVM(VmSnapshotListModel.java:703)
    at org.ovirt.engine.ui.uicommonweb.models.vms.VmSnapshotListModel.executeCommand(VmSnapshotListModel.java:912)
    at org.ovirt.engine.ui.uicommonweb.UICommand.$execute(UICommand.java:163)
    at org.ovirt.engine.ui.common.widget.action.UiCommandButtonDefinition.$onClick(UiCommandButtonDefinition.java:130)
    at org.ovirt.engine.ui.common.widget.action.UiCommandButtonDefinition.onClick(UiCommandButtonDefinition.java:130)
    at org.ovirt.engine.ui.common.widget.action.AbstractActionPanel$11.execute(AbstractActionPanel.java:575)
    at com.google.gwt.user.client.ui.MenuBar$1.execute(MenuBar.java:893) [gwt-servlet.jar:]
    at com.google.gwt.core.client.impl.SchedulerImpl.runScheduledTasks(SchedulerImpl.java:164) [gwt-servlet.jar:]
    at com.google.gwt.core.client.impl.SchedulerImpl.$flushFinallyCommands(SchedulerImpl.java:270) [gwt-servlet.jar:]
    at com.google.gwt.core.client.impl.Impl.exit(Impl.java:378) [gwt-servlet.jar:]
    at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:335) [gwt-servlet.jar:]
    at Unknown.Ix/<(Unknown Source)
    at Unknown.anonymous(Unknown Source)