It's been a while since I last used the Data Explorer, although any query I try now comes up with nothing, for example:
I'm trying to query data from stackoverflow.com. Is there something wrong with it?
EDIT: Apparently the
Switch sites option at the bottom of the query page was doing the opposite of what I thought:
I had mistakenly assumed the site which I was querying was stackoverflow because of the icon that was currently showing — it was actually the site it would switch to upon clicking it. As a suggestion, if there was an indicator of which site was currently set to query upon a quick glance of the page it would be helpful and perhaps avoid similar confusion by others.