Imported courses (CC and BB formats) aren't showing?

[occam2436]

I'm a courseware developer.  I've been writing SCORM packages, but now the trend seems to be toward Canvas.  Several customers need to use the package in Canvas, and most Canvas installations don't have the SCORM import ability.   I've got a Canvas sandbox account, and I've exported a package from Blackboard in both CC and BB formats.  The Canvas sandbox imports both of these successfully into a Course, and shows them as Published, but I can't get either of them to actually open and run the content.  Obviously I'm missing some wildly obvious and simple step, but I can't seem to find it!   Do the Sandbox accounts NOT actually run and view the content?  Is that the missing fact?  Or is there a step AFTER publishing that I'm not taking?