Issue with Embedded Signing Client URL s

Question

I'm using the Docusign SOAP API to embed a docusign template in a Visualforce page. When the document is signed I would like to redirect to another page. I am using the ClientURL but it doesn't seem to be working. When I sign the document and hit Finish, I get the Please wait modal and it just stays there. Any idea what the issue could be? Code snippet is included below. Let me know if you need additional information. Thanks!

DocuSignAPI.RequestRecipientTokenClientURLs clientURLs = new DocuSignAPI.RequestRecipientTokenClientURLs();
clientURLs.OnSigningComplete = 'https://zzz-dev-ed.my.salesforce.com/00QG000000w0ZsaMAE' + '/' + '&event=OnSigningComplete&envelopeid=' + envelopeID;
    try {
        token = dsApiSend.RequestRecipientToken(envelopeId, recipient.captiveinfo.ClientUserId, recipient.UserName, recipient.Email, assert,clientURLs);
    }  catch ( CalloutException e) {
        System.debug('Exception - ' + e );
        errMsg = 'Exception - ' + e;
        return '';    //TODO: send to error landing place
    }