Why won’t my PowerPoint save as a MP4?

Why won’t my PowerPoint save as a MP4? Right-click on Microsoft Office 2016 and choose Change. If there are 2 repair options, select Online Repair, then click on the Repair button. If there is only one repair option, select it, then click on the Continue button. Allow the process to complete, restart your computer, then see if you can create an mp4.