I can't finish the tutorial - it stops on "add instrument"

I try to pass through the tutorial but it hangs on “add instrument” topic. There are no possible action after that, the only thing I can do is to finish the tutorial.
The same thing in a working mode - when I select “add instrument” item nothing happens.
What the problem is?

I use Android application.

The app needs to connect to the n-Track servers at least once to download the list of available instruments, make sure that the device is connected to the internet. If the problem persists try killing and restarting the app.

Flavio.