Error when open word document in .NET

System.Runtime.InteropServices.COMException: Could not open macro storage.


object missingValue = Type.Missing;
Line 339: object fileName = "C:\\CsharpCustomizedLetter\\Templates\\" + clr.ToUpper() + ".doc";
Line 340: oApp.Documents.Open(ref fileName, ref missingValue,
Line 341: ref missingValue, ref missingValue, ref missingValue,
Line 342: ref missingValue, ref missingValue, ref missingValue,

Getting error message on Line 339:

Can anyone help me out...

Thanks in advance