Good day, betsyclemons.
QuickBooks Mac Desktop 2016 is upgraded to run on macOS Sierra. Make sure your QuickBooks is updated. To update QuickBooks:
- Go to QuickBooks.
- Select Check for QuickBooks Updates and follow the on-screen prompts to install.
You can also check out this article: https://community.intuit.com/articles/1197915
Let me know if you're still encountering issues after attempting these