MIDI notes suddenly go silent in Retrologue

All I did was select an instrument, start to play it and, within seconds the filter cutoff snaps to zero. I gave none of these instruments commands of any kind - and it’s a drag not to be able to use the VST Vintage Classics Instrument package I paid for. I’m a bit hesitant to spend good money on add-ons that corrupt the instrument; this didn’t happen before I downloaded it…