I did reinstall macOS Ventura 13.6, removing Sonoma 14.1, but it didn't help. I guess my Time Machine backup brought with it all the problems that began when Ventura updated to 13.6.3. I even took my MacBook to Apple to reset it and they reset it to Ventura 13.6. Unfortunately when I installed BootCamp Windows 10, it blew out my macOS and when I revived it, it was back to 13.6.3. I cannot open any company file even on a fresh install of Ventura. Tried some of the key combinations but not the command+password entry yet. I'm suspecting that there are still some support files involved that are mucking up the operation. Similarly, a fresh install of QBDT 2019 will not even launch on the Mac Studio M2 running macOS 14.1.3. Don't understand why this is as others have reported success. Maybe I need a newer installer of QBDT2019?
