I'm seeing the following JavaScript error in Chrome when logged in:
Exception in module-execute in module ext.wikimediaEvents.loggedin:
TypeError: mw.Uri is not a constructor TypeError: mw.Uri is not a constructor
This currently occurs for me on all pages on ca.wikipedia.org and pl.wikipedia.org, but not other sites I've tried. @jrobell
reports the same issue on es.wikipedia.org. When logged out, the error does not occur.