Originally Posted by
scaryjim
Probably because ...
Chances are the file was corrupted when Powerpoint froze and closed whilst saving.
I don't have Powerpoint 2016, but in 2010 there's an "Open and Repair" option - rather than double clicking the file, open Popwerpoint from the Start menu, go the 'File' tab, choose open, navigate to your file, click it once, and you'll see the open button has a little down triangle next to it like a drop down list. If you click that you'll get a drop-down menu, and one of the options on that should be "Open and Repair". Give that a go.