Load XML file from XNA

Question

Hey guys,
        
        I'm facing a problem in my 2D Level Editor game. I create a level and save each object's position, texture, size, geometry and body (using Farseer Physics). When it comes to loading this level this message is shown:("There is an error in XML document (40, 10).") and inner exception ("Object reference not set to an instance of an object.").


Can anybody please give me a hint?

Thanks