Thanks for your reply, dziegman!

I haven't tried on a separate computer, but my WiFi connection is stable. I was able to download the Presentation in .pdf form earlier, but that is of little to no help. Your last questions prompted me to attempt to download two presentations at once so that it would create a .zip file. Both presentations opened and worked fine. If I try to download it by itself, it is still giving the same error messages. Now that I have a workable copy, I'll just be working directly in PowerPoint. Thanks for your insight!