Landscape Material ORD Issue

Im fairly new to learning Unreal and running through a few startup tutorials. I’m creating a landscape Master material and I can’t get the ORD Textures from Megascans to work correctly.
I’m getting this error in my Material Instance


I can’t work out how to separate out the Roughness/Ambient Occlusion/Displacement channels from the Texture
My Material is this

with the roughness

I’ve unchecked the sRGB box on the texture import setup. In fact it was already unchecked.
I’ve had a look at the Megascans master material M_MS_Surface. It does look different to mine, so i tried copy and paste their nodes to my master material and it just goes all wrong from there.

I would assume its something very simple that I’m not aware of yet though.
I just wish to have a simple master material that i built from scratch in order to understand what is going on, otherwise I’d just use the megascans master which at some point will leave me with a hole in my knowledge

Thanks