Screenshot

Steps to reproduce:

1.Open a page with VE
2.Insert a media
3.Open the media Settings for the image

Observed Result:
The caption field is missing in the media settings dialog box .Also in the console the following error appears:

Uncaught TypeError: Object #<OoUiButtonSelectWidget> has no method 'initializeSelection'

See the screenshot attached

Test Environment: http://en.wikipedia.beta.wmflabs.org/
Browser: Chrome Version 26.0.1410.65
OS: MAC OS X 10. 8. 5

Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=63544

Attached: