js error IE10 no editor
Edit a URL that does not exist e.g.
http://en.wikipedia.beta.wmflabs.org/wiki/0.721023e4802348
Click Create source
The wikitext editor sometimes not appear at all.
When this happens the error is 'unable to get property 'appendChild' of undefined or null reference'
See screen shot.
Also, styling from the ProveIt gadget sometimes appears also, even though ProveIt is unselected in Preferences for this user.
See screen shot.
Version: 1.22.0
Severity: normal
Attached: