Bad importing 3D objects (no textures/skins appears!), what could I do?

Hello, I'm trying to import 3D objects like 3DStudio / Blender ones, but I can't see right colors in theme. In what I experienced it seems like textures were not correctly loaded, very strange because I imported one single file with no other directory or extensions.

Here some few examples:


Could you help me please solving this problem? Thanks, salvatore

Look at this answer try it

See this link: It explains where Unity tries to locate textures.