add to group and cancel buttons no functional

search for contacts.
select 50 of them.
select add contacts to a group from the drop down menu.
click go.
select a group.
click add to group button.
nothing happens (same behavior for cancel button).

selected contact should be added to the specified group.

Same behavior no matter how many contacts are selected.

Same behavior for ALL drop down selections... tags, delete, saved search, etc.