UMG Children broken in Build packaged with Nativization

Child widgets not visible when packaged with inclusive nativization on.

"The problem is that ChildWidget never shows up in the package build, but shows fine in the editor. I've debugged the issue a bit and found that the main problem is here:

1. void UChildWidget_C_pf1010915279::_CustomDynamicClassInitialization(UDynamicClass* InDynamicClass)
2. {
3. ...
4. auto _Local_0 = NewObject<UWidgetTree>(InDynamicClass, UWidgetTree::StaticClass(), TEXT("WidgetTree"));
6. InDynamicClass->MiscConvertedSubobjects.Add(_Local_0);
8. }
9.  

Basically the problem is that the WidgetTree that gets constructed for this class doesn't take it's parent UMG tree into account and just creates an empty widget tree object.

When this is later on passed to UWidgetBlueprintGeneratedClass::InitializeWidgetStatic, it never initializes bpv_TextBlock_106_pf.

This means the logic wont work and the visuals are missing."

Also confirmed in Main CL# 4319846

Example project attached

1. Create a Widget with a text box
2. Create a Child Widget of this widget
3. Add widget component to actor and set widget
4. Place actor with widget in world
5. Enable Inclusive Nativization
6. Package

Result: Widget is not visible