QuickBooks backup file will not open

This just happened when I click file. "QuickBooks can not open this company file because it was created with an incompatible version." What the heck does this mean?

Yes. In a recent update to QuickBooks for Mac 2016, Intuit changed the file format of the Company file and changed the QuickBooks app so that it will no longer run on Yosemite, only El Capitan and Sierra. That means that if you are still running Yosemite and your bookkeeper runs the updater, you can no longer open your QuickBooks Company file unless you update to El Cap or Sierra, something that I'm not able to do because I have to maintain backwards system compatibility with other software like FileMaker Pro. I have complained loudly and emphatically to QuickBooks TS about this but their answers about whether there will be a patch to allow the new file format and app to run on Yosemite are non-committal.

I know you don't want to do either but I think the first option is the best. It isn't callous disregard - most people want to run QB Mac on Sierra and we are doing everything we can to make that possible. People actually stuck running it on Yosemite still have the option to do so - they just can't run the latest release. I don't think this is the situation for Nina.

Source: community.intuit.com February 19, 2017 – 21:32