Thanks for sharing the error message you've got, BarbQ.
I'm here to help you open your company file in QuickBooks for Mac 2019.
When opening QuickBooks for Mac, you can press and hold down the Option key. This will avoid loading a company file. Next, choose QuickBooks and select Check for Updates. Then apply them and open the company file again.
To update QuickBooks Desktop for Mac, check this article: Update QuickBooks Desktop to the latest release.
These troubleshooting steps can resolve errors when opening a company file. I'd appreciate if you can update me on how it goes. I'll be here if there's anything else you need. Have a good one.