Resolved.
Still trying to remember who told me / where I heard that when running a program, it must be executed from outside the directory. That's what I had been doing for the past week. This time, I compiled from inside the directory where the .java file was (like I normally do), but
stayed there and ran
java MainProgram, still from within the
Test folder. That worked.
Campbell: No package declarations are used right now - I simplified the program to the very basics - one file inside one folder. I stored it on the desktop as a temporary location just to troubleshoot this problem. And no more screenshots! OK
Daniel: I removed the \bin portion of my HOMEs
Junilu: Thanks for the awesome mini-tutorial. I'll come back to this post periodically because it's covered so many details that it'll be useful moving forward. I'll remember how to run a program when it belongs in a package.
You all have been an awesome help. Definitely bookmarking this post.