Quote Originally Posted by lat9 View Post
The USPS API has done it again; they've changed the branding for the Priority Mail and Priority Mail Express methods from a trademark (TM) to a registered-trademark (RM), which results in a mismatch when the shipping module attempts to locate methods returned.

An update will be available later today or tomorrow. Thanks, @HeleneWallis, for the notification and your help.
I am happy to buy a cup of coffee to anyone who can provide an update to fix this issue! Customers are unable to checkout!