If it matters, this is on Windows 11 Pro

Please try uninstalling and reinstalling the program using the download from our website here: https://turbotax.intuit.ca/tax/software/install

If you are still not able to resolve the problem, please contact our phone support team at 1-888-829-8608 (Monday to Friday, 9 AM to 6 PM ET) for more assistance.

Thanks for the reply.  

After uninstalling, downloading from the link you supplied, and trying to reinstall, I now get the error during the installation 😥

Sorry to here that. Our phone support team (1-888-829-8608) can do more advanced trouble shooting on problems like this. 

After a pretty lengthy discussion with a very helpful support agent on the phone, it appears that Turbotax has  a dependency on a particular version of the Visual C++ runtime that is out of date, and won't install if you have a newer version that is actually supported :(

Not a great experience...  I'll have to try installed on a older PC rather than one that is running a fully supported OS.