You may have received this error for a number of reasons. However, more than likely it's because your shipper number (Account Number) from the Shipping API was not added to your ups.com profile.
To verify you have the correct information in your ups.com profile:
UPS tracking solutions show the progress of your shipment every step of the way, across town or around the world.
Track packages and find UPS locations while you’re on the move with our mobile tools.