Why won't Windows 10 cooperate with Power Point 2013?

[Windows Central Question]

When I try to open a downloaded power point from eCampus.wvu.edu, I receive a message "PowerPoint found a problem with content in [download file]...PowerPoint can attempt to repair the presentation." Then I click "Repair" and the following message appears "Sorry, PowerPoint can't read [downloaded file]". The Show Help tab tells me to turn off my antivirus, which I am more than a little hesitant to do. Is there any way to fix it? I have tried to download it to my computer first, and then open it in PowerPoint, as opposed to opening it straight from the browser, but I get the same result. If you have any suggestions, it would be greatly appreciated!!