It's sad that MM has let the MIDI Tool go to seed, and left it in the dark ages. More than sad, it's pathetic.
Do you have the right channel set in the Score Manager?
You're probably in ReWire mode
Try right clicking on the installation file, and choose Run as Administrator
Yes, but, but my point is that it's unlikely for MM to make that request to Plogue
Since Finale doesn't support VST3 that request seem unlikely
Since nothing show up for audio drivers it's probably not a Finale issue. Do you system sounds or YouTube playback?
A 4K monitor has the space of 4 standard HD monitors. To run at 100% scaling you really need a 40/43" monitor. The default Orchestral score takes about 18 vertical inches.
Rather than 2 monitors, I'd recommend a single 40+" 4K display. I got one a couple of years ago and I'd never go back to a double monitor setup.
If you have the demo installed can't you just activate that?