Configuration of views with entity reference fields
The images are referenced to the main content type via an Entity
  Reference field.


Who has the entity reference field? The Main content type (aventuras)?  OR the Images content type? 

Based on your question, I will guess the Main content type.

If the Main content type has the entity reference field, then under Advanced you need to add a relationship of Referecing and NOT Referenced Entity (notice the bold endings). 

Also, no need to add a relationship in the image field.