Waldy wrote:
> I am trying to use this in a standard .Net configuration file.  Hi The 
> encoding is declared at the top of the file as utf-8. 

Just saying that the file is encoded in UTF-8 doesn't mean that it is.
Like putting a label on your toothpaste tube that says "Tomato puree" 
doesn't make it tomato puree. The file has to BE in UTF-8.

> I get an XML 
> exception when I use the umlaut, "Invalid character in the given encoding". 

That indicates that the file is not in UTF-8.

> If I change it to ä I get the error "Reference to undeclared entity".

Correct. If you want to use named character entity references you must 
declare them in a DTD or an internal subset, eg

<?xml version="1.0"?>
<!DOCTYPE whatever [
<!ENTITY uuml "&#228;">
]>

> I have however tried using &#228; again and it works!  

Yes, numeric references work everywhere.

> I don't know what happened the first time, but thanks anyway. 

Check the encoding of the file. If it's not UTF-8, use iconv or whatever 
the equivalent is in Windows to convert it. If you can't convert it, 
change the encoding declaration to say what is really being used (eg 
ISO8859-1). Leaving it broken will cause subsequent users problems.

///Peter
-- 
XML FAQ: http://xml.silmaril.ie/