Weird scenario. I saw a very unclear question that already had a down vote. I thought I saw the name of the OP before, and clicked his name to look for familiar questions. Then, I pressed 'back' in the browser to return to the post, and pressed the 'Close' link.
The popup that should let you pick a reason now was empty with only the X to close it. After refreshing the page, the question appeared to be closed already. Usually this results in an orange popup telling you that it is closed already.