How to reproduce
- Make a change in the UI Builder (such as changing text size/colour)
- Click on a 2d sprite and click on the sprite editor button in the inspector
- Make a change to the 2d sprite and click close

Actual result
*You are now presented with a dialog box stating that you will lose any unsaved changes in UI Builder.

Expected result
Either changes are not lost or on opening the sprite editor the user is warned about the potential for data loss and is allowed to save any unsaved work.