C#: "Unable to load" file error on executing System.IO.File.WriteAllLines( ls_PathAndFile, ls_aLineText )

Question

While overwriting an xml file through following steps:

1. Read all contents of an xml file in an string array: string[] ls_aLineText = System.IO.File.ReadAllLines( ls_PathAndFile );
2. Overwritten contents of the ls_aLineText array
3. Overwriting the xml file using: System.IO.File.WriteAllLines( ls_PathAndFile, ls_aLineText );

Steps 1 and 2 execute correctly, but step 3 displays the error "Unable to load" xml file. Please suggest ways to overcome this issue.

Thanks in Advance

Vivek