However when I tried updating to OS 10.12, QB 2010 did not work, so I had to downgrade it back. What I'm currently using is QB 2010, believe it or not, and though it was intended for OS 10.7 or something, it's just fine on 10.11, because of continuing updates. But I do want to bring things a bit more up to date and it's QB that's stalling that out. I have a very small business, my accounting needs are minimal, and I am simply not going to upgrade the Mac, the OS, or QB to the latest and greatest.
I asked a few months ago here about updating QB for Mac (desktop) on my old 'cheesegrater' Mac Pro.