Implicit truncation of vector type issue


I am getting a strange issue with this material layer, Its rendering fine in the Mat function editor but when I plug it into my material layer stack its giving me an error.

[SM5] /Engine/Generated/Material.ush(2657,2-65): warning X3206: implicit truncation of vector type

I have narrowed this issue down to the input texture I am using, as I don’t get the error if I swap the texture for something else.

The compression settings are the same so I am a little stumped.

I am an artist so I have zero knowledge of code, so please keep it simple for my small brain.