Just Not Getting It
I have a perfectly good website running PP Express, I've decided to make some changes to the checkout methods and put it over to a testing server.
I've changed the Payment Gateway to the PP sandbox account, checked the boxes on all the relevant pages for "Sandbox"
It fails every time with
Security error</ShortMessage><LongMessage xsi:type="xs:string">Security header is not valid</LongMessage><ErrorCode xsi:type="xs:token">10002</ErrorCode>
Don't know what I'm missing here, I've double checked the "Sandbox" boxes and checked and the authority code