Video file is not readable when trying to upload

I recently downloaded a zip file with two .mov video files in it. Once I unzipped the file onto my Android phone (HTC One), I converted the file using a Media Converter app. I can play the file on a VLC player, but when I try to upload it to any social media (Instagram and Facebook), it doesn't even show up as an option. What can I do to change that? I need it to be able to upload in this fashion for work and have been trying to do this for the last 24 hours with no luck. Any suggestions please???