Also try this. Maybe it helps.
Ensure that:
- the Bluetooth remote device to operate the MPE is working (battery OK and no Bluetooth interference issue);
- the I/O master switch on the MPE module is in position "I"; click to "O" and "I" again;
- the grey plug cable is properly plugged in; pull out and plug in again.
Picture below: master switch in position "I" and grey plug unplugged:
For the "MPE Hack": see
here.