Screenshot
Steps to reproduce:
1.Open a page with VE in FireFox
2.Click on the Categories button to open up the dialog box to add categories
Observed Result:
TypeError: response.visualeditor is undefined appears in the console
See the screenshot attached
Test Environment: http://en.wikipedia.beta.wmflabs.org/
Browser: FF 25
OS: MAC OS X 10. 8. 5
Page:http://en.wikipedia.beta.wmflabs.org/wiki/3rd_janff?veaction=edit
Version: unspecified
Severity: normal
Attached: