Yeah, connect MPP midi out to a synthesizer, such as this
https://coolsoft.altervista.org/en/virtualmidisynthit looks like it creates a MIDI out device so you should see it available in MPP.
Usually the sound cuts out when your computer reaches its limits; more powerful computers can handle more notes. But if your computer is reasonably poewrful but cannot handle even a few notes, I'm not sure what would be responsible... but I think it may be your “sound card”. I once tried using a USB headset which I believe has its own little sound card thing inside, and MPP notes would cut out more easily than it did with regular headphones (and then that stupid thing just stopped working... “Microsoft Lifechat” it was)
if you're using a desktop then you could install a better sound card in an expansion slot. Otherwise... maybe you can use a USB sound card, if you can find one that's actually better