Crash when using Vertex painter with material including cubemap texture sampler

Engine crashes when static mesh have material with cube sampler in vertex painter mode.

Simply DaylightAmbientCubemap_Mat have texture cube as texture sampler.

This is not reproduced in 4.15 version.

Also, This is not reproduced when Switched to vertex painter mode first then apply material.

1) Place a cube into viewport
2) Select Painter mode (Shift+2)
Notice the Engine does not crash

3) Select Place mode(Shift+1)
4) Find DaylightAmbientCubemap_Mat in the Engine contents.
5) Apply the material over the cube
6) Select Painter mode(Shift+2)

Notice the Engine crashes.

Casts.cpp
[Link Removed] [Link Removed]

> UE4Editor-CoreUObject-Win64-Debug.dll!CastLogError(const wchar_t * FromType, const wchar_t * ToType) Line 10 C++
UE4Editor-MeshPaintMode-Win64-Debug.dll!CastChecked<UTexture2D,UTexture>(UTexture * Src) Line 217 C++
UE4Editor-MeshPaintMode-Win64-Debug.dll!FPaintModePainter::CacheTexturePaintData() Line 2211 C++
UE4Editor-MeshPaintMode-Win64-Debug.dll!FPaintModePainter::Tick(FEditorViewportClient * ViewportClient, float DeltaTime) Line 2109 C++
UE4Editor-MeshPaint-Win64-Debug.dll!IMeshPaintEdMode::Tick(FEditorViewportClient * ViewportClient, float DeltaTime) Line 436 C++
UE4Editor-UnrealEd-Win64-Debug.dll!FEditorModeTools::Tick(FEditorViewportClient * ViewportClient, float DeltaTime) Line 717 C++
UE4Editor-UnrealEd-Win64-Debug.dll!FEditorViewportClient::Tick(float DeltaTime) Line 1174 C++
UE4Editor-UnrealEd-Win64-Debug.dll!FLevelEditorViewportClient::Tick(float DeltaTime) Line 2063 C++
UE4Editor-UnrealEd-Win64-Debug.dll!UEditorEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 1701 C++
UE4Editor-UnrealEd-Win64-Debug.dll!UUnrealEdEngine::Tick(float DeltaSeconds, bool bIdleMode) Line 386 C++
UE4Editor-Win64-Debug.exe!FEngineLoop::Tick() Line 3119 C++
UE4Editor-Win64-Debug.exe!EngineTick() Line 63 C++
UE4Editor-Win64-Debug.exe!GuardedMain(const wchar_t * CmdLine, HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, int nCmdShow) Line 169 C++
UE4Editor-Win64-Debug.exe!WinMain(HINSTANCE__ * hInInstance, HINSTANCE__ * hPrevInstance, char * __formal, int nCmdShow) Line 199 C++
[External Code]