Using sencha generate app in extjs 4.1 (sencha cmd v 4.0.3.74)

Hi, i'm trying to use the cmd in my app, i'm new with cmd so checking the documentation i read that I have to create an app from my extjs folder so i have the structure to start with.

In my cmd (windows 8) I run the comand sencha generate app MyApp MyApp

and i get the next error:

Unable to locate framework.dir property from sencha.cfg



I need something else? where should i run the cmd?





Regards