Could not update and cannot now install Fusion 360 on my MacBook Pro

[kurt]

This started with trying to load a file I had been working with on my up-to-date copy of Fusion on my PC and finding that it said the file was created on a newer release of the app and could not be opened. I would normally see the app updated automatically on both PC and Mac. But it turned out it was not updating on the Mac. I've tried all kinds of things suggested by the install process, but have gotten nowhere. The log file is attached. I'm hoping the fact that my Mac can no longer be updated with OS X due to its age is not the issue. I do not know what database disk image is being referred to in the log.

[jhackney1972]

Take a look at this webpage and see if it helps you out.