I have updated to the latest version and have followed the four steps to get my app setup and have the consumer key and secret but I am getting this error at check out.
Authorization failure. Perhaps username and/or password is incorrect.

I have verified that the key and secret are correct. What do I try next?

Is this UPS shipping rates that is giving the problem? Normally it isn't problematic to tell the truth once you have the correct credentials. Have you tried UPS support to make sure the details you have are correct?

Vince

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