MuseScore 3.5.2 does not playback

1. After I updated MuseScore to 3.5.2, I opened an existing score. See attached: Smugger's_Song-my revision.mscz
2. I altered several notes (click+dragged to new position on staff,) and saved.
3. I attempted playback by pressing the space bar. "Play" arrow turned blue, but playback did not happen. I pressed it again to stop (it did), and clicked the "rewind " arrow+bar, then the "play" arrow. No playback.
4. I created a new document, basic treble clef, instrument=guitar, left rest at default (4/4 time, 24 bars.)
5. I went into Notation mode (keyboard: "N") and placed several 1/4 notes. I then exited Notation mode, clicked "rewind", and "play." At this point, MuseScore locked up. (Window went hazy, top bar said "Not Responding".) After 2 minutes, I clicked the "X" to close.
6. I reopened MuseScore, recreated the new document as before, and could not play back the notes. (No crash this time; "play" arrow did turn blue.)
7. As I was typing up my bug report online, I switched back to MuseScore to check my steps. While I was in the program, the system crashed (Blue Screen, Stop code: KMODE_EXCEPTION_NOT_HANDLED.) While I'm not 100% certain MuseScore caused this, it did happen while I was using the software so I'm including this in my report. (I also had Firefox and Foxit PDF Reader open at the time. I'm running Windows 10.)
8. At this point, I'm saving this bug report, and will attempt to reopen MuseScore.

I've only used MuseScore for a few months, so I apologize if any of this is caused by my faulty usage. (The software is remarkable -- very comprehensive, yet easy to get started with.)

Thank you!