If the files NIHardwareAgent and/or NIHostIntegrationAgent are missing in the list, add them by clicking the ' +' icon and navigating to the following location:.Open your Mac's System Preferences and choose Users & Groups > Login Items.

This issue can be caused by the following: You cannot hear any sound when playing the keys of your KOMPLETE KONTROL S-Series keyboard and it is not available as a MIDI device in the KOMPLETE KONTROL Preferences.