You have a post from last year about VIs randomly stopping working (
https://duc.avid.com/showthread.php?t=417609) folks offered suggestions there, but you never replied to those folks trying to help you. Is this related to that? (If so please reply there, don't start a new thread).
You "loaded up a track?" You mean you opened a session? or project?
Sounds like you've got a complex set up with VEP and a third party VI and MIDI driving two tracks. And you sound a bit lost. Start with a new empty session (not from template and not a cloud project) with MIDI grand installed on a instrument track and get that working. No VEP, no dual tracks, no setting yourself on fire and shooting yourself out of a cannon.
But most worrying is "after trying everything" is pretty lazy and tells us *nothing* useful. What *exactly* did you try? Do you expect folks there to waste their time repeating stuff you've already tried or interrogating you to what you have already tried?
So have you checked the most basic stuff? No MIDI getting to the instrument track is usually either MIDI through not being checked or the track simply not being record armed. Is the MIDI device listed and enabled in the Pro Tools MIDI input devices? If it plays to the stand alone VI it tells you the device and driver is working.
While MIDI data is likely the issue you can also check if the the VI is working. Can you mouse click on MIDI grand keyboard in the plugin GUI and hear stuff? See track meters move?
And you are going to try trashing prefs because all Pro Tools troubleshooting always starts with trashing prefs. read "help us help you" up the top of every DUC web page.