Quicktime player quits
I have a new MacBookAir 2020, Catalina OS 10.15.4, 13in. Running Quicktime Player 10.5
I've only had the Mac for 2 months. Quicktime used to work fine. Now it closes after 10 seconds of being open. Regardless of playing a video file, or just opening the player and waiting- after 10 seconds it closes. Every time. Then a message box appears saying QuickTime Player quit unexpectedly- ignore, send report, cancel. I performed the built-in diagnostic and no problems were found. And I made sure nothing external was attached that might not be compatible with the Mac. Is there a way to repair it? I only see older versions to download on this website. This is my first Mac so this is a real bummer.
Thanks for any advice.