Preston,

The second URL you referred me to had the solution.

Under the settings for Firefox, click on "Options" and then on "Security".

You want to uncheck the box next to "Warn me about unwanted and uncommon software".

And that solves the problem.

I just re-downloaded the products with Firefox and they both came through just fine. Also, scanning the downloaded files with Avast and Malwarebytes indicated that they were clean.

Thanks for steering me to those two sites, Preston.

I can only presume that a Firefox update somehow changed that setting.

best, Dave