I developed a scanner application for the device Motorola MC45.
But sometime for some of the devices the scanner getting stopped/not responding.
While I pulled the log files from the devices I observed that the devices are having the below mentioned exception.
 
ArgumentNullException  
System.ArgumentNullException: ArgumentNullException 
   at Symbol.Marshaller.SymbolMarshal.MarshalDwordTo(IntPtr pPtr, Int32 nOffset, UInt32 uValue) 
   at bp.o(ReaderData A_0) 
   at Symbol.Barcode.ReaderData.d(Object A_0) 
   at System.Threading.ThreadPool.WorkItem.doWork(Object o) 
   at System.Threading.Timer.ring()
 
Is there any specific reason for this exception?
How to prevent/handle these kind of exceptions?
After this issue how to enable the scanner again?

Thanks in advance.