UMG 3D "Cast to" crash [4.6.1]

Access violation - (first/second chance not available)

UE4Editor_CoreUObject + 497120 bytes
UE4Editor_CoreUObject + 1555428 bytes
UE4Editor_CoreUObject + 1153450 bytes
UE4Editor_CoreUObject + 689886 bytes
UE4Editor_CoreUObject + 1157578 bytes
UE4Editor_CoreUObject + 1149510 bytes
UE4Editor_UnrealEd + 9739282 bytes
UE4Editor_UnrealEd + 10074675 bytes
UE4Editor_UnrealEd + 10045544 bytes
UE4Editor_KismetCompiler + 369435 bytes
UE4Editor_UnrealEd + 9881482 bytes
UE4Editor_Kismet + 727159 bytes
UE4Editor_Kismet + 992849 bytes
UE4Editor_Kismet + 1007926 bytes
UE4Editor_Slate + 588774 bytes
UE4Editor_Slate + 1535133 bytes
UE4Editor_Slate + 1030727 bytes
UE4Editor_Slate + 1037049 bytes
UE4Editor_Slate + 1435577 bytes
UE4Editor_Slate + 2116506 bytes
UE4Editor_Slate + 2296435 bytes
UE4Editor_Slate + 432060 bytes
UE4Editor_Slate + 160583 bytes
UE4Editor_Slate + 832224 bytes
UE4Editor_Slate + 770598 bytes
UE4Editor_Core + 2484713 bytes
UE4Editor_Core + 2400763 bytes
UE4Editor_Core + 2489275 bytes
UE4Editor_Core + 2387186 bytes
user32 + 105425 bytes
user32 + 104666 bytes
UE4Editor_Core + 2490486 bytes
UE4Editor!FEngineLoop::Tick() + 3434 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\launchengineloop.cpp:2193]
UE4Editor!GuardedMain() + 479 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\launch.cpp:131]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.6\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]