Invalid_Security - Invalid public hosted page url in signature - [/apps/publichostedpagelite.do ]

[CameronGoss]

Hi 

I am trying to set up an HPM 2.0 page. 

I am generating the signature credentials and passing them in params to the Z.render method.

function loadHostedPage(params) {
            Z.render(
                params,
                prepopulateFields,
                callback
            );
        }

My signature, token and key all validate successfully, but I am then presented with an error:

"Invalid_Security - Invalid public hosted page url in signature - [/apps/publichostedpagelite.do ]"

The URL to which it refers is the URL provided to me by zuora when setting up the HPM page: 

https://sandbox.eu.zuora.com/apps/PublicHostedPageLite.do

I have searched the web and cannot find any suggestions about the URL giving an error. 

Any suggestions?