Video doesn't play: "Content-Type" of "text/plain" is not supported

I’m using rtMedia on a BuddyPress site. It appears that I can upload video just fine: I upload the video, and the player appears. But when I click the video, it says the video length is 0 and it doesn’t play - the spinner icon just spins endlessly. When I hit “play” with the Firebug console enabled, I get the following error:

HTTP “Content-Type” of “text/plain” is not supported. Load of media resource http://url-of-video.mp4 failed.

What can I do to fix this?

Check settings in rtMedia for allow media type under rtMedia->Settings->Types. The video must be enable.

Video is enabled - that’s not the problem.

Any more suggestions about what I can do to fix this problem? I can give you admin access to the site if that would help.

Hi Morgan,
just for reference, can you check it in chrome as well? Also make sure your none of the browser addons creating conflict which prevent to load video files.

It works in Chrome, but not in Firefox.

Hi Morgan,
I just checked our demo site -> in firefox and is working fine. Let me know if that works in your system or not?

The demo site works fine on my computer.

I tried disabling all plugins, and that didn’t help.

Hi Morgan,
I am sorry to say but I can’t help you as our demo works perfectly fine and not your site. Have you tried default WordPress theme? Also check on fresh WordPress setup.