XOS GUI Become Irresponsive

HOW TO REPRODUCE:

1. Start fresh CiaB
2. Create slice `mysite_foo`
3. Create instance `mysite_foo_instance` using medium flavor
4. Wait maybe 5-10 seconds
5. Delete Slice `mysite_foo`
6. At this point, three red popups will start appearing, for ControllerNetwork, Instance, and ControllerSlice
7. I fooled around looking at Slice and Instance admin pages, eventually settling on the instance that has been deleted
8. In the instance admin, I pressed `?` and `/` a few times
9. The GUI froze and Chrome popped up "Page Unresponsive"