Please make sure that:
your MIDI device is enabled in menu File > Audio and MIDI Settings > Device > Active MIDI Inputs (standalone mode only).
you have enabled Record for your instrument/MIDI track in your DAW (plug-in use only) – e.g. here is how the record button looks when enabled in Pro Tools:
you have selected the correct MIDI Port and Channel in your Part – if you have any doubt, please select Omni (i.e. multi-channel).
- you are playing notes in the valid range.
- you are not triggering notes from a multi-out preset that is routed to separate plug-in outputs.