FedEx will be performing routine maintenance on their API/rates system on September 5th that will affect order checkout on live online stores.
Merchants using FedEx rates may not be able to generate live FedEx shipping rates in the checkout area of the online store(s) during the following time-frame:
Start Date and Time: Saturday, September 5, 2015, 9 p.m. CT
End Date and Time: Sunday, September 6, 2015, 1 a.m. CT
Duration: 4 hours
If you are using FedEx as your only shipping provider, it is recommended to switch to flat-rate shipping during the above time time or put our store in maintenance mode.
If you are using other rate providers along with FedEx (i.e. USPS, UPS, etc), your checkout system will continue to return rates from the other providers and only exclude the FedEx rate options during the scheduled FedEx downtime.