TMDL view

[DevisSs]

 I'm working with TMDL View, very easy operations like put measures in a folder or something like that. It happens that the after pushing "Apply" on TMDL View, if I try to save the file an error message arise:

"Non è possibile salvare il documento" stand for it is not possible to save the document. What figure out under that string is that the path in which my pbix file is stored is not valid. 
Generally, this error arise when I start to work in the View. You may say " why don't you use a project to work with TMDL?". The error arise as well. Tryied! Above all, apply changes it Trasform data in PBI is a lot much faster in pbix than in pbip so for a matter of efficiency I switched on pbix, but this is another problem.
Some suggestion?