Created attachment 1218460 [details]
Logs

Description of problem:
[UI] - Creating new disk in a new VM dialog triggers a ui exception.

- When creating new vm and choosing to create new disk as part of the vm creation, once pressing the 'ok' button to approve the disk creation a ui exception is thrown is the fronted ui. 

2016-11-08 11:14:40,307 ERROR [org.ovirt.engine.ui.frontend.server.gwt.OvirtRemoteLoggingService] (default task-1) [] Permutation name: 97A602FFE25E72EDDB47BBC28FFBC1DE
2016-11-08 11:14:40,310 ERROR [org.ovirt.engine.ui.frontend.server.gwt.OvirtRemoteLoggingService] (default task-1) [] Uncaught exception: com.google.gwt.event.shared.UmbrellaException: Exception caught: Exception 
caught: (TypeError) 
 __gwt$exception: <skipped>: Cannot read property 'b' of null
        at java.lang.Throwable.fillInStackTrace(Throwable.java:114) [rt.jar:1.8.0_111]
        at java.lang.RuntimeException.RuntimeException(RuntimeException.java:32) [rt.jar:1.8.0_111]
        at com.google.web.bindery.event.shared.UmbrellaException.UmbrellaException(UmbrellaException.java:70) [gwt-servlet.jar:]
        at com.google.gwt.event.shared.UmbrellaException.UmbrellaException(UmbrellaException.java:25) [gwt-servlet.jar:]
        at com.google.gwt.event.shared.HandlerManager.$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.CustomButton.onBrowserEvent(CustomButton.java:631) [gwt-servlet.jar:]
        at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1648) [gwt-servlet.jar:]
        at com.google.gwt.user.client.impl.DOMImplStandard.dispatchEvent(DOMImplStandard.java:320) [gwt-servlet.jar:]
        at com.google.gwt.core.client.impl.Impl.apply(Impl.java:296) [gwt-servlet.jar:]
        at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:335) [gwt-servlet.jar:]
        at Unknown.eval(webadmin-0.js@54)
        at com.google.gwt.dom.client.DOMImplStandard.$dispatchEvent(DOMImplStandard.java:68) [gwt-servlet.jar:]
        at com.google.gwt.user.client.ui.CustomButton.$onClick(CustomButton.java:822) [gwt-servlet.jar:]
        at org.ovirt.engine.ui.common.widget.dialog.AbstractDialogButton.onClick(AbstractDialogButton.java:45)
        at com.google.gwt.user.client.ui.CustomButton.onBrowserEvent(CustomButton.java:631) [gwt-servlet.jar:]
        at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1648) [gwt-servlet.jar:]
        at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1666) [gwt-servlet.jar:]
        at com.google.gwt.user.client.impl.DOMImplStandard.dispatchCapturedMouseEvent(DOMImplStandard.java:352) [gwt-servlet.jar:]
        at com.google.gwt.core.client.impl.Impl.apply(Impl.java:296) [gwt-servlet.jar:]
        at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:335) [gwt-servlet.jar:]
        at Unknown.eval(webadmin-0.js@54)

- This is not preventing from the disk creation if pressing another time on the 'ok' button, the disk is created and the vm as well.

Version-Release number of selected component (if applicable):
4.0.5.5-0.1.el7ev

How reproducible:
100%

Steps to Reproduce:
1. Create new vm and choose to create new disk as part of the vm creation. Press 'ok' to approve the creation of the new disk.

Actual results:
UI exception is triggered and displayed.

Expected results:
Should work as expected without any ui exceptions.