Media Player just keeps loading

Using mac, when I press play on the video file, the loading bar just comes up and keeps loading…and loading…and loading…

Can you tell us what file type the video file is?

it seems to work on the mobile app on my ipad, but not via the pc app (on mac) or web.

the video is mp4

Theres a lot of reasons that could be, the most common is that its different codec in an mp4 file, and its confusing the web browser, since youre a mac user it could be a mov file in an mp4? since that is not web streamable

If other videos work for you this is most likely the case