MICROTONE 5000, new free Microtonal VST. 64-bit Windows. New from BipTunia Synths: https://biptunia.com/?p=10403
MICROTONE 5000 is a VST3 and VST2 Polyphonic analog-style synth with 5000 microtonal tunings (also has western 12-TET setting), 128 presets (also can be user configured), 2 oscillators, 2 filters, 1 LFO, 7 LFO assigns, and 6 voices. It has very low CPU usage.

your VST seems fine but problems with path are sucking a lot, so I never (never) was able to launch .mid files… 🙁
sorry
Path for the tuning files?
Do the presets work for you? they also have some, there’s 128 of them, gives a lot to work with.
If you’re using the VST3 and can run VST2s, try the VST2, it automatically loads presets, and uses relative paths, so if you install it as as described in the PDF it should at least pull up the preset tuning files correctly.
VST3s have issues with presets on many DAWs, by defaults. The creator of the standard broke something that didn’t need fixing. VST2s “just work” and with my VSTs there is ZERO reason to run VST3 instead of VST2 if you can run VST2. (a lot of people say “VST3s are better” without being able to explain why, I have found.)
If you installed the VST3 more than a week ago, re-download it, it now includes a separate folder of the presets and step by step directions where / how to install it.
https://biptunia.com/?p=10403
What DAW / OS are you on, just for curiosity.