QuickBooks has determined that the 2015 and 2016 discontinued versions of QuickBooks Desktop for Mac are not compatible with Apple’s new MacOS, Catalina – which was released by Apple on October 7, 2019. Use of these discontinued versions of QuickBooks Mac with Catalina may cause data loss or crashes.
Intuit has alerted their Mac customers through email and in-product messaging.
Here is a link to an article on at QuickBooks with information on: The risk of data file corruption and data loss for QuickBooks Desktop for Mac users who attempt to run QuickBooks on macOS Catalina.