it returns an object that represents the requested resource object otherwise, null if a resource object is not found or if a resource object is found but it does not have the requested property.
string x = (string)GetGlobalResourceObject(Resource1, value);
so when you try to cast a null to a string its nothing.
so this will not be an exception like tat in file read, where it returns an exception if the file not found.
the only exception thrown by the GetGlobalResourceObject is MissingManifestResourceException which returns the string 'A resource object with the specified classKey parameter was not found'
if your output says like GetGlobalResourceObject not found try qualifing that with the httpcontext class. eg HttpContext.GetGlobalResourceObject()