Image widget not showing up when a material is applied and a text block is placed over it

If an image is added to a UMG widget with a material applied to it. It will no longer show up in the viewport if a text block is added to the same widget (above the material via the Zorder).

1. Open Editor
2. Create a new widget
   Right click content browser > User Interface > Widget Blueprint
3. Create a new Material
4. Open new Material
5. Create a constant (Make it any color other than black)
6. Connect the constant to the emissive pin
7. Under Usage in the details panel check Used with UI
8. Click Apply
9. Close Material
10. Open Widget
11. Add an image (Make it really large so that it's easy to see but leave a place to drop a text block)
12. Apply newly created material to the brush image of the image widget
13. Add a text block to the designer graph and change its ZOrder to 1
14. Drag text block over the image
15. Launch game in a standalone (it must be a standalone. the error will not occur with PIE)

[Repro/Test Included] UMG Materials Not Displaying In External Windows

[Bug 4.6 Preview] UMG Image as material wont show in Standalone