MIDI File Woes

Hi everyone,
 
I’m using Sonar Professional v23.10.0 Build 14 and I’m a novice.
I have some MIDI files that were created over 20 years ago on a Yamaha PSR-SQ16 keyboard/sequencer workstation.
I’d like to use these files to recreate the music using modern voices in Sonar Pro. I think I’m right in saying that I need to use a soft synth plug-in to send the MIDI data to in order for it to provide the voices, so I think I’ve set that up correctly using Rapture Session.
 
The problem I’m having is that, when I play the MIDI files using Rapture Session in Sonar, the on-screen meters move as expected but there’s no sound. Even when I display the Rapture Session user interface and click on the virtual keyboard there’s no sound.
I know that my system is set up correctly because I’ve successfully used Sonar and Rapture Session to create new music using my MIDI controller keyboard. It’s only when I attempt to use these old MIDI files that the problem occurs.
 
One thing I’ve noticed about the Sonar workflow for these old files is that there are some vertical bars displayed and I’m wondering if they are some sort of MIDI instruction that Sonar doesn’t understand, such as the voice selection data, causing it to fail. I have no idea if it’s possible to analyse this data to find out what it’s supposed to be doing.
 
Can any of you seasoned experts provide some guidance or are my old MIDI files doomed to the waste bin?
 
Many thanks for reading.

Hi and thanks for the reply. Yes I've directed the output of the various MIDI tracks to rapture session. I don't know what NRPN or RPN events are so I need to do some research. I've tried Cakewalk TTS and the vertical lines in the MIDI workflow silence this too.

EDIT: when I change the output to Miscrosoft GS Wavetable Synth I get sound. This is all a bit baffling and frustrating!