Had that once with international but I did create CA shipping labels yesterday PM and had no issues.
Is the street address over 40 characters long?
In rare cases it will not work, without there being an apparent reason. This has happened a few times over the years and PP support was unsupportive. However, it has to do with something on the buyer side I sensed. Perhaps the buyer having issues with his PP account?
In such cases we go directly to PP shipping and enter the address manually. That always seems to work.
Bernie