Back from breakfast. In the meantime it occurred to me that an easier way to setup a test was to just rename the profile folder to "xprofile" so that it wouldn't be recognized and a 'virgin' web-browser could be used. So I did that with Iron. That enabled me to get the links to Mike's google-drive using Palemoon and paste them into Iron's URL box.
I had no problem downloading zoom, or the two applications keniv just mentioned: Iron 32-bit and palemoon, both 32-and-64 bit.
Now to see which addon generates the problem. I suspect either or both the two I mentioned. I'll install adguard first.
Installed Aguard into Iron. No problem downloading vivaldi. No problem downloading Google-Chrome portable with both Adguard and Privacy Badger installed. Those were the primary suspects. I'll have to change the current profile's name, and remove the x from the old, and re-launch Iron to see what else I might have done.
Nope. Those were the only two.
For some reason I had to rebuild iron's profile. In doing so I set Iron to "Block third party cookies." Guess what. Now I couldn't download google-chrome portable but received a notice that I could find out why. I clicked the offer and the webpage which opened advised, among other things, that "Blocked Third-party cookies can prevent Drive Web downloads." 
Talk about Google wanting to know everything everyone does. 
There appears to be a way to configure settings to specify "sites that can always use cookies." I wonder if by 'site' a specific google-drive is possible, or to access a specific google-drive must I authorize cookies for everything on 'google.com'?
I've had enough diversion for the day. I'll opt for the 'work-around': Download-All; let google zip and download all.
Still, I wonder if that means I'll have to download everything from one of Mike's 'here's a bunch of stuff' folders the next time he places a new goody into it?

And on the third hand, I had no problem downloading amethyst's EssentialPIM.sfs. Amethyst doesn't set-up a separate mdsum download; well, any mdsum for that matter.