This article is meant to be an on-going repository of "gotchas" and best practices for SCORM Engine server setup. When issues are related to a .NET or Java specifically, that will be called out.
Problem: When launching a single sco package the player exits right after launching, despite the sco window still being open.
Solution: The client was calling the web server with host name which was defined locally in it's hosts file... like lms.company.com. The webserver itself resolved lms.company.com to something completely different. This doesn't seem like it would be an issue. And interestingly, you could pop open an .aspx page and scoWindow.closed would remain false. But if popuplauncher opened an html file, scoWindow.closed would be true and the player would automatically exit. The solution was to put an entry on the web server's hosts file that mapped lms.company.com to the same thing as the client. This was likely an IIS quirk.