Thanks. I noticed that after reading another post from 2009. I made those changes and then tried it and the error doesn't occur now. However, now when I go through the checkout I get a checkout failure.
For the checkout failure page I bound the following to help see what the problem is:
<?php echo $_SESSION["RoyaleCart_USPS_ResponseCode"]; ?><?php echo $_SESSION["RoyaleCart_USPS_ErrorCode"]; ?><?php echo $_SESSION["RoyaleCart_USPS_ErrorDescription"]; ?>
The response I get is:
0 80040b1a UspsCom::DoAuth
What does this mean?