I get the attached crash when trying to drag-drop the attached texture into a sub graph. The textures .meta has been attached so you can see how it is being imported.

To reproduce:
1. Create a new sub graph asset
2. Drag/drop the attached texture into the shader graph window

Expected Result: a SampleTexture2D Node is created
Actual Result: Crash

On further investigation it appears simply attempting to create a SampleTexture2D Node in a Shader Graph Sub-Graph fails..?

Repo'd on DX11