Applying material to imported mesh

Hello, I started using Unreal engine to render the 3d models i create using sketchup, but i’m encountering a problem that i can’t solve,
So i used another software to import assets and materials for Unreal Engine, but i can’t apply them to the elements of my 3d model, it could work only for meshes created using Unreal Engine,
I discovered that there is no problem with the materials on the starter content.
(i did this with 3ds max but it didn’t work).
Thank you!!