URGENT! Texture undefined before and after building

Hi all,

I have a problem with the definition of the texture. I start importing a mesh when is applied a modifier UWUnwrapp in 3DsMax. Into Unreal, I create material and apply it on my mesh. Firstly the definition of the texture is correct. After same operations with other mesh, suddenly the definition of the texture of some materials became orrible. Into the material editor, the texture in the SampleTexture is correctly visualized, but in the preview the texture on the sphere is not correctly defined. Help me please, is the third time that i re-create my level from the import of the meshes. What i am doing wrong?

Thanks in advance