Can you see the drop down? (That status area where it's located can be hidden and even locked.)
When you click on it is it nonresponsive or does it just not list any layouts?
In layout setup or manage Layouts, you can specify whether a layout is included in this list when the system is in browse mode. In Layout mode, however, you should still see all layouts listed.
It's unresponsive when it browse mode, but drops down just fine in edit layout mode.
Then Open Manage Layouts... and see if any of the check boxes to the far left of the listed layout names are selected. If all the checkboxes are cleared, there will be no layouts listed in the drop down when you are in browse mode. To add a layout to the list, select its check box.
It worked! And now that I think back, I recall about an hour ago when I unchecked those because I had to delete a layout.