This error happens when you try to use a property or call a method of an object that is null. More details: here
A simple use of Visual studio DEBUGGER can tell you the object because of which it is happening. Just look at the stack trace and put a debugger on that line. Check the objects of that line and see if any one is null and you are trying to use that objects property. Handle the same.
Above, looks like objDyn is NULL
or one of the parameters passed
assuming error is not raised in