I have an issues a few times this week. I am unable to cancel/exit from a pop up (at the moment its my 'Select Remittence to email' pop up. I can select which ones I want, send etc but it wont let me get out of it. So I am unable to complete any other tasks. It happened a few days ago and the only way I could fix it was to wait for the session to timeout. Which isn't always viable when I need to work.