When this happened to me, I found the midi lead connecting my Foot Controller to the KN7 was very loose in the socket. Changed it for another lead and no further problem.

The only other time this happened was when a friend had used my KN and had used his own settings, knocking my own out. My Foot Pedal was set as a Fill-In and his was set to STOP, hence the reason my KN went silent on me. Needless to say, I now check that the Data Protection is set to 'ON' before I start playing to an audience.

Hope this helps.

Audrey