UMG bug with event dispatcher in Mobile preview and device

I double post here and in answers hub

I’m running engine latest preview tag (4.6).

I have found a mismatch between play in editor and mobile preview / device.

Use case: Create an UMG widget (parent). This widget creates other UMG widgets (childs).

The childs widgets intend to communicate with the parent widget using a Call to event dispatcher which the parent exposes and binds to a custom event.

This works flawless in Play in Editor / New editor window. But fails in mobile preview editor. I can see this in the log:

[2014.11.10-21.11.12:985][115]LogBlueprint:Error: [compiler] Error Could not find an event-dispatcher named “InventoryItemClickedDispatcher” in ‘Inventory_C’.
Make sure ‘Inventory_C’ has been compiled for Call InventoryItemClickedDispatcher