So we are uploading videos in preparation for launch of Stream. Most are fine, but some have no video, only the audio plays. The strange thing is that they are all cut from the same footage, so we cut into sections, upload them separately, and some don't work. They are all the same format. They play locally. If we download them from Stream, they also work, so the upload seems OK. If we delete from Stream and then upload again, there is the same issue.
This happens in IE11 and Chrome, for all users when viewing affected videos.