Due to a change FedEx made to their API over the weekend, we had to update the third party shipping library we were using. This had to be done for not only FedEx, but UPS and USPS as well. You will find that the error information will be more helpful when setting up your methods. But, the new library seems to be more accurate and less forgiving. Because of that, we highly suggest that you test any active shipping methods you are using in your stores for accuracy and adjust if necessary. Please submit a ticket to support if you have any difficulty.