Android Question Creating an embedded directory...

Hi everybody,
I have to create a directory tree:


This code return no error but /fotoaffissioni/invio/ is not created.
I previously created /fotoaffissioni/ with this code:

B4X:

 If File.Exists(File.DirDefaultExternal,"/fotoaffissioni/")=False Then File.MakeDir(File.DirDefaultExternal,"/fotoaffissioni/")

and the directory is there...

Has anybody some hint for me?

Thank you in advance

Mauro