Audio and video uploads not working in old versions of WordPress < 4.4
We’ve received a couple of reports that audio and video file uploads don’t work anymore in old WordPress versions (4.3.9 and lower). You instead see the message “HTTP error”. (This doesn’t affect uploads of images, PDF files, etc.; it affects things like MP3 files and movies.)
This is because of a bug in the WordPress software itself, which will presumably soon be fixed, and not related to our servers.
However, if this is happening to you, you’re using a very outdated version of WordPress. You should update to the current version 4.7.3, which is easy to do by clicking “Updates” in your WordPress dashboard. We recommend that you always update WordPress whenever it tells you to do so, because it avoids all sorts of problems.