If I look at the dataset view, and check a bunch of images, then I choose Action: Set Tag(s), I get a dialog box. I enter my tag and press "return" or I click on the submit button and it appears as if nothing happens.

I can't make the dialog box go away unless I click on "Cancel". Then, I look and see that the batch tag operation DID take effect.

But my only way out of the dialog box is to "cancel".