Click-and-Ship Page Sticks Prior to Final Screen

Click-and-Ship allows me to input recipients address and all other information but when clicking to proceed, it returns the message "You have made changes to your label information that require rates to be recalculated, please click the button below once all of your changes are completed." All is checked and correct, no changes have been made. At top of page it says " unexpected error has occurred. Please try refreshing the page." But refreshing the page loses all information entered. I've tried this from three different computers at two different physical locations, with exactly same results. I send parcels this way often and haven't had this particular problem before.