vertex blend material not working

so trying this tutorial Vertex Blend Material with UE5.2 ive selected the 3 material instances through content browser, when i select create material blend i get the error message “current material blending setup doesn’t support more than 3 materials” even tho I’ve only selected 3, anyone seen this?

Yes, that happened to me, too, and I’m confused at the moment

I’ve found a solution, and I hope this video helps