Importing models - Texture disappears

[WALP]

you dont need to create a material file first.
What you need to do is to not use the model editor to import your mesh because its not made for that.
Instead export your model as collada with the texture assigned and in the right location, then open it in the model viewer and if everything is done right it should generate a new mat. with the name of your texture, which you can then open and edit with the material editor.
If you cant get it to generate a material though it wont hurt to make it manually like sona suggested