Reverting to 16.64 did not resolve this problem for me but attempting to do so fixed it. Here's all of the steps I took including the important deviation that made a huge difference.
- Launch Auto Update and Disable Automatic Updates
- Use UninstallPKG to remove the Microsoft Excel package.
- When uninstalling a package there is an advanced options setting. I have all of these on which removes preferences and attempts to remove any directories created by the package so that nothing is left behind. I think this setting was key to resolving the issue.
- Installed the 16.64 from the download link in your post.
- Opening the Excel file with 16.64 still gave me the error message about being unable to update the stocks, so I gave up and ...
- Used the Auto Update Tool to upgrade to the latest version.
- When I opened the Excel file with 16.69 the problem was gone.
I don't know exactly what I did to fix it but I highlighted the step that might have made the most difference. I'm not really sure why this didn't fix it for 16.64 as well but since I no longer have the problem I cannot test it further. Hopefully this helps someone resolve it and we can narrow down a set of minimal steps to fix it.
But does 16.69 continue to work correctly after exiting the program and then reopening it? Because I found that I could get it to work but it broke again after exiting. On the other hand, I found that 16.64 did NOT work initially but after I exited and then reopened it began to work properly and has continued to work properly with multiple exits and reopenings. Very strange.