just wanted to post an update: still having trouble with the "helloworld" file. One of my friends tried it, and was able to get it to work successfully. He sent his zip file to me, and I was able to upload it to the application installer successfully, but nothing displayed on the Roku.
So, I copied his file exactly, and upon uploading my version, the application installer promptly rejected that, as it has all of my other attempts.
So now, just for kicks and giggles, I tried to upload his file again...the exact same file that was accepted successfully before gave the same exact error that my files have been getting.
I searched the forums on this error, using "Install Failure: No manifest. Invalid package" as my search terms. It seems that most people that were having this problem were either working on Mac OS X (which, btw, I'm working on Windows 8.1), and/or they had their manifest at the wrong level (buried in the "source" folder, or otherwise not at root level).
btw, for further information, here are the contents of my manifest file (should look familiar...this is exactly how it shows up in the SDK example):
title=Hello World
subtitle=Simplest Program
major_version=1
oh, and I've tried everything else, too...tried to install VisualStudio and Eclipse...neither seemed to want to have anything to do with BrightScript. Tried both Juno and Helios versions of Eclipse, the update site for BrightScript wasn't recognized, and thus couldn't even use it for this project.
Does anyone have any ideas? I swear I've gone down every single rabbit hole...not one of them has produced a single carrot!