Excel new/edit External Data Query hangs
 

When I go into Data/Get External Data/New Database query (or Edit Query), it
just sits there. The database is Oracle, but I don't even get the dialog box
to pick a data source. It worked until a couple of days ago.

Any ideas what might be wrong? I don't know of anything that changed during
that time. In fact, it worked one minute and didn't the next.