I can’t figure this one out and I’ve been on it for 2 hours now.
I’m trying to play a Rhodes sample loaded into Halion 3 using an MPK88 controller. The samples play fine, until I hit the sustain pedal, then they cut out, as if it’s getting a “note off” message.
The pedal has been set up correctly (cc#64), and works fine with previosu projects. I’ve looked at the Halion GUI and don’t see anything unusual about CC#64 on its options page.
This has me baffled
Try a new blank project and/or power cycle everything.
This is ridiculous – if I use the USB option for this board, that’s when it doesn’t work – my controller has a midi monitor and it’s showing a “note on/note off” message along with the cc#64 data. If I lose the USB and just use traditional MIDI cables, everything works fine.
I have had more problems over the years with USB when it comes to MIDI 
Just a thought! are the controller on/off the right way round?
Does the sustain pedal itself have a polarity switch ?