Object reference not set to an instance of an object.

I'm loading dll using reflection. So while invoking method "Object reference not set to an instance of an object" error occurred. My Code is :

string strAssemblypath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase);
                    System.Reflection.Assembly objASM = System.Reflection.Assembly.LoadFile(strAssemblypath);
                    Type ty = objASM.GetType("MSOCBM");
                    Object obj = objASM.CreateInstance("MSOCBM");
                    System.Reflection.MethodInfo MorphosMethod = this.GetType().GetMethod("Capture");
                    object[] parametersArray = new object[] { 0, 0 };
                    MorphosMethod.Invoke(obj, parametersArray);

Error occurred on last line.

Thanks in advance !!