If a user has the rights to edit a data source but does not have the rights to change permissions, the UI allows a user to make a change to the access control settings and attempt to save. The save fails due to the lack of rights to change permissions, and a message to that effect is shown, but the UI begins to spin and the buttons remain disabled. The workaround is to refresh the page.
Ideally the controls to change access control should be disabled if the user does not have the right to change them. At a minimum the cancel button should be enabled (and spinning stopped) when the change attempt fails