Resolved error message when rehashing a downloaded game save

I am following the tutorial step by step but every time I go to rehash and resign I get a error message saying
Unhandled exception has occurred in your application. If you click Continue,the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.
Object reference not set to an instance of an object.

 

Have you tried updating your netframe work try downloading this mate - http://www.microsoft.com/en-us/download/confirmation.aspx?id=17851

 

Okay cheers mate I'm downloading it now we'll see if it works

 

ok man

 

did the net thing work for you cause if so im going to try it because im getting the same message

 

i get the same thing, but i let it go and it works, huh? try using a different save editor program like there's modio and 360 revolution and horizon and xbox 360 tools by xb36hazard
i dont get errors using xb36hazard but thats just me and my pc

 

ok.

 

The net thing didn't work but I'm going to try to use horizon but does anyone know how to do it on horizon?