There seems to be a minor bug that, when you click the custom offtopic reason text box directly, rather than the radio button that comes with it, switching to a different offtopic reason will keep the vote-to-close button in the state it was in for that text field, rather than enabling it.
I can reliably reproduce it doing the following steps:
- Obtain some close votes
- Find a suitable candidate to close
- Click close
- Click "off-topic because..."
- Click the radio button "Other (add a comment explaining what is wrong)"
- Click any other offtopic reason
- Click inside the text box containing "This question appears to be off-topic because it is about" (that is: NOT the radio button. You have to click the text box). Since this is not a valid off-topic reason, the vote to close button will be disabled.
- Click any other offtopic reason. (The vote-to-close button stays disabled)
This happens at least on Google Chrome 36.0.1985.125 m and Internet Explorer 11. I haven't tested other browsers, but I have no reason to believe it is limited to those browsers only.
Clicking any other offtopic reason but the custom one will fix it.
Screenshot showing the problem. Hand-drawn circle is added free-of-charge.