instantiate the template created by Devart sqlite for dot.net

I would like to know if anyone can enlighten me , I read the documentation but either way I do not work , that is not me instantiates the model visual studio .

Should instanziarsi MainEntities but also the IntelliSense of visual studio does not recognize me the model , although the solution there is.

documentation aims to instanziarlo as you would any other object :

MainEntities db = new MainEntities ( ) ;

but this does not work , I have no results . I 'm probably missing in a teacup ?

Thank You