I get a message box telling me to download an update. After it downloads and extracts, I select install and relaunch and nothing happens, and the software closes.

[MichaelMc]

I have not been able to duplicate the results you are reporting. Have you verified having enough space for the install to run properly on your drive? This could be one explanation for the behavior you are describing.

If you have not recently done so, my immediate suggestion would be to update your OS. I am running TurboTax on a MacBook Pro using Mac OS Mojave version 10.14.2, installing frequent TurboTax updates, and having no issues.

[cfukami]

I waited overnight, tried again, and it worked.  There must have been some kind of glitch.  Thanks!