Sharepoint – Infopath : Schema validation found non-datatype errors

You may get the ‘Schema validation found non-datatype errors’ when opening an InfoPath form after it has been updated programatically.

Cause is -
White space is not being preserved when using xpath to update the form.

Solution is set PreserveWhiteSpace =True on XMLDocument object.

XmlDocument originalDoc = new XmlDocument();
s = originalItem[0].File.OpenBinaryStream();
originalDoc.Load(s);
originalDoc.PreserveWhitespace = true;