This affects production (at least MediaWiki.org) and betalabs:

1. Go to any Flow board and click on the default sort order and select another sorting option.
2. Click to post a new topic - 'Post a new message..' area will display the old-style wikitext icon
3. Enter a title and some content in CE area - click 'Add topic' - the entered topic cannot be posted.

The Console displays:
An invalid form control with name='topiclist_content' is not focusable.

This affects other actions too.