Ted here from Shopify!
Can I ask where are you seeing this error appear? How have you connected with UPS within your Shopify admin? If you could provide a screenshot I'm more than happy to have a look into this with you.
Feel free to reach out to our Support team any time as well. We're here 24/7 via chats, emails and phone. Just click 'talk to support’ for some more info!
All the best,
Thanks for letting me know! The error you are seeing was a known shipping error that was occurring for some stores on the 16th of October. The issue has since been resolved, however, if you are still seeing an error please contact our support directly. We would be happy to take a closer look into this with you.
If there is anything else I can help you with, please let me know.
Thanks a mill,