Articulate Replay not working in SharePoint (2013)

I've published my screencast with Replay, and have a perfectly functional mp4 file on my desktop.  When posting to SharePoint on a Media Library webpart, I am able to view my video to my heart's content but no one else can.  I really think this is more of a SharePoint issue that an Articulate issue, but I thought I'd give it a try.

A little more info, SP Site/Library Permissions seem normal.  But who knows?  

Also, for every other document or media type there is a "check in" component when posting to a SharePoint list or library, and I am not seeing that with my Replay mp4's.  In fact, there's a link in SP settings called "Manage Items Checked Out" (or something like that?) and all of my mp4's are listed there - none of them having an option to check-in.

Like I said, I am able to view my published/posted videos, and while others can see the link or thumbnail for my video, when they click it says "Media Failed to Load."

I'm at a loss!  Any thoughts or suggestions would be greatly appreciated.