The AJAX loading indicator is not removed when the resulting response from confirming an action does not contain a message (using MESSAGE_TITLE and MESSAGE_TEXT).

The code in question is the else below from core.js. It closes the dark layer but not the loading indicator.

				// If a confirmation is not required, display an alert and call the

				// callbacks.

				if (typeof res.MESSAGE_TITLE !== 'undefined') {

					alert = phpbb.alert(res.MESSAGE_TITLE, res.MESSAGE_TEXT);

				} else {

					$dark.fadeOut(phpbb.alertTime);

				}