"Object reference not set to an instance of an object" in binary deserializing

Question

I am Serializing a class object and storing in sqlite database as BLOB from a C# application.

Function used for serializing: public static byte[] ObjectToByteArray (AnalyzeSubstring obj)

And on other application, fetching the blob database and converting blob database in to the object by deserializing. function for deserializing is :public static AnalyzeSubstring ByteArrayToObject (byte[] arrBytes)

public static byte[] ObjectToByteArray (AnalyzeSubstring obj)
              {
              if ( obj == null )
                  return null;
              BinaryFormatter bf = new BinaryFormatter ();
              //bf.AssemblyFormat = System.Runtime.Serialization.Formatters.FormatterAssemblyStyle.Simple;
              MemoryStream ms = new MemoryStream ();
              bf.Serialize (ms, obj);
              return ms.ToArray ();
              }

          public static AnalyzeSubstring ByteArrayToObject (byte[] arrBytes)
              {
              MemoryStream memStream = new MemoryStream ();
              BinaryFormatter binForm = new BinaryFormatter ();
              memStream.Write (arrBytes, 0, arrBytes.Length);
              memStream.Seek (0, SeekOrigin.Begin);
              AnalyzeSubstring obj = (AnalyzeSubstring) binForm.Deserialize (memStream);
              return obj;
              }

Issue:In line while deserializing AnalyzeSubstring obj = (AnalyzeSubstring) binForm.Deserialize (memStream);.

It fails with error

Object reference not set to an instance of an object .

However if we do both operation in same application only, then this work properly.

Please help