Ok, I have it working properly now for the Warehouse pop-ups and dialogs.
Given that I completely uninstall IE, I played a hunch that Make2017 is making IE calls to a library that I may have uninstalled. So, I re-installed IE11 (still leaving Firefox as default, with no desktop shortcut, etc.) to see if a missing library was re-installed.
It looks like that was the case, as immediately after the re-install, Make2017 pop-ups displayed /operated properly.
I may delete the IE11 executable anyway (just because I will not use it), but I won’t do a complete uninstall, so that the probable library being called stays…
anyway, thanks for the info. You put me on the right track to solve it.