FaceBook callback problems need help

I need some help with a FaceBook callback problem.

In PHP you need to do this with a callback


And I am trying to figure out how or why this is not working

var rc = event.getCollection();
var email = mailService.newMail();
email.setTo( “andrews@andyscott.id.au” );
Email.setType( “html” );
savecontent variable=“local.mailContent” {writeDump(rc);}
email.setBody( local.mailContent );
mailService.send( email );

Now I am getting the emails very much so when the callback is being called, and the variable hub.challenge is defined. Yet the logs are showing that the renderData is throwing an error that it is not defined.

Anyone have any ideas this has got me stumped.