According to the Microsoft documentation, the .NET class
System.Xml.XmlWriter.WriteString() does the following:

"Character values in the range 0x-0x1F (excluding white space characters
0x9, 0xA, and 0xD) are replaced with numeric character entities (�
through &#0x1F)."

However, when we call WriteString() in an application we have written, we
are seeing the following exception being thrown:

System.ArgumentException: '', hexadecimal value 0x12, is an invalid
character.
at System.Xml.XmlUtf8RawTextWriter.InvalidXmlChar(Int 32 ch, Byte*
pDst, Boolean entitize)
at System.Xml.XmlUtf8RawTextWriter.WriteElementTextBl ock(Char* pSrc,
Char* pSrcEnd)
at System.Xml.XmlUtf8RawTextWriter.WriteString(String text)
at System.Xml.XmlUtf8RawTextWriterIndent.WriteString( String text)
at System.Xml.XmlWellFormedWriter.WriteString(String text)

Anyone ever seen anything like this? Any idea what I am doing wrong?

Tom Delany