What you are describing is not a typical use case. Normally, an e-learning course would be enabled with links to open static files (*.pdf, for example) or web pages. Pointing a course to open another *.story file would most likely give the result you are seeing (a blank screen), since other users would not always have the Articulate software required to open the file.
If you really want to have the user open and launch a second e-learning course from the first one, you will probably have to publish one or both of them to a SharePoint site. You could also (I think) launch a Rise course hosted on a web site from a link in a Storyline course, but like I said, this is not typical.