I'm not sure yet if this is a bug in MediaElement or the Media module.
Drupal and module versions:
- Drupal 7.0-dev
- Media 1.x-dev
- MediaElement 1.0
- Styles 2.x-dev
- WYSIWYG 2.x-dev
Here are detailed steps to reproduce:
- Configure the WYSIWYG to support the Media Browser button
- Configure MediaElement.js to "Enable MediaElement.js site wide"
- Go to Configuration/Media Types/Video/Manage Display
- Go to the "Large" display format
- Set the format to "MediaElement Video"
- Create a new piece of page content
- Use the Media Browser button in the WYSIWYG to select an uploaded video file from the library
- Set the Current Format option to "Large"
- Click the submit button
This error only happens when one or more of the display formats is set to "MediaElement Video".