I am using an app that is bundled with this book:
MacOS 10.12.3 (16D32
MacBook Pro (15-inch, 2016
NPAPI Plug-in version 126.96.36.199 is installed
My quiz app window needs to be resized. Below is the video showing the smaller quiz window and out of sync with the mouse.
Also below is a pic of the mProjector.
I know this doesn't help, but it looks like a problem with the content, and something the author ultimately needs to correct. As you can see the user interface is rendered at about 1/4 the size of where the actual hit areas are. They're doing something clever, like calculating all of the content on the page to scale to an arbitrary display size, but they've got math wrong (probably because high-density retina-style displays didn't exist when they wrote the code).
Each of the major browsers handles scaling a little differently, and you might get lucky and find one that just works. I assume you're using Safari, so give Firefox and Chrome a shot.
Short of that, you could reach out to the content author for support, but it's ultimately not a problem with Flash Player itself. You're more than welcome to refer the content author to this thread. They're welcome to private message me (just click my name), and I can point them to some good resources for properly handling this kind of scaling problem.