Problem with MIDI input or with the screen keyboard?

In Pizzicato 3, it sometimes happens that the MIDI input does not work or that the piano keyboard (Windows menu, Piano keyboard) is not reacting as it should. To correct that, go in the Options menu, MIDI setup... Double-click the left MIDI input and go in the "MIDI filter" button. See that every check box is checked in that dialog (except the System exclusive, which is not necessary). Validate and close the dialog and the problem should be solved.