IE10 not playing a video when using the <video> tag, but plays it when requesting the video directly

Question

I have a webpage with a tag on it with the following markup:

Answer 1

I would check whether the mime-type is correctly being returned for the file.

Chrome will play correctly regardless of the MIME Type returned.

To check:

1. Press F12 to display the IE Tools Window/Pane.
2. Go to the Network Tab
3. Click Start Capturing
4. Browse to the page in question
5. Find the mp4 line
6. If the Type is displayed as application/octect-stream then this is your issue.