I am getting this error and I am stumped.
Before you ask, yes I am on the production server. The USPS guy tells me that I need to debug the error messages I am receiving (I don't get any) and that I need to follow the steps in the API instructions (I thought ZC was already set up to automagically do all the API stuff).
Here's the error I'm getting:
We are unable to find a USPS shipping quote suitable for your mailing address and the shipping methods we typically use.
If you prefer to use USPS as your shipping method, please contact us for assistance.
(Please check that your Zip Code is entered correctly.)