[Slate] UI not appearing when playing in viewport

[ue4-archive]

When we run our app in a new window or as a standalone game, our UI appears just fine.

When we run it in a viewport in the editor, the Slate UI doesn’t appear at all, even though all the initialization code appears to be running identically in that case (the HUD is correctly adding the master widget’s content to the game viewport, and our master widget’s Construct() is getting called as expected and running properly).

Why might this be? Is there a hidden setting somewhere that disables Slate when running in a viewport?

[ue4-archive]

This is currently disabled because running Slate in viewport exposes potentially dangerous abuse of global variables. These improper use cases of global variable are being cleaned up. Until they are all gone, we are erring on the side of safety and hiding all the Slate Game UIs inside the viewports.