[BUG] UE50 / 51 crashes if you try to add ScreenUV Lerp With Color to Material Output Pins

Development Rendering
,
1

No idea why but Unreal crashes if you try to make a lerp with viewport uv and put in some material output pin (like emissive, base color, etc).

(basically if you connect the setup below to any of the pins)

UnrealEditor_sxNuxyCwHV
UnrealEditor_sxNuxyCwHV559×543 52.5 KB

Crash log:

Assertion failed: bAllowNonFloat [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Materials\HLSLMaterialDerivativeAutogen.cpp] [Line: 156]

UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_CoreUObject
UnrealEditor_MaterialEditor
UnrealEditor_MaterialEditor
UnrealEditor_MaterialEditor
UnrealEditor_UnrealEd
UnrealEditor_GraphEditor
UnrealEditor_GraphEditor
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_Slate
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
UnrealEditor_ApplicationCore
user32
user32
InkObj
atlthunk
user32
user32
UnrealEditor_ApplicationCore
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

Tested both in 5.0 and 5.1.

Also reported bug to unreal - it goes by the case number below.
Case # 00486273: Unreal crashes if you try to add ScreenUV Lerp With Color to Material Output Pins

2

Update - Unreal accepted it as an issue - Unreal Engine Issues and Bug Tracker (UE-167126)