When I test a map in the console appears this sentence:

SOLID_VPHYSICS static prop with no vphysics model! (models/mapmodels/barbed_wire.mdl)

Why is this happening? What does it mean? How can I solve this error?

Thanks in advance.

It means that the barbed wire model does not have so called "vphysics". The vphysics is the part of the model that interacts with (blocks) the player and bullets.

To get rid of this error you have to switch the collision setting for the model, choose "not solid". If you want it to block the player you can make some clip brushes on the appropriate places.

Thank s Nubbits :D

Or contact the model author and ask them to make a physics hull for it.