I think I have this bug isolated. World space coordinates plugged into a normal map crash the editor if the material has Render after DOF enabled on a translucent material. If I use regular Texture Coordinates it will compile in preview 7. I already submitted a bug report but I can be much more specific about how to reproduce it so maybe I’ll submit a new one.
Update: It compiles if tessellation is turned off on the material. Just another bug related to the broken tessellation.