I get this error when I fail to ‘clean up’ my UTF-8 MemoryStream: “Invalid at
the top level of the document. Error processing resource…” Visual Studio 2005
in debug mode shows well formed XML “prepended” with a character represented
by an empty rectangle and trailed with a series of backslash zeros (\0).
These are the lines of code that solve this problem:

s = s.Trim();
s = s.Replace("\0", String.Empty);

The Trim() gets rid of the “prepended” mystery character and the second line
explains itself. Why do I need these two line of code? Here is more context:

MemoryStream ms = new MemoryStream();
XmlTextWriter xw = new XmlTextWriter(ms,Encoding.UTF8);

//do XMLWriter stuff…

xw.Flush();
s = Encoding.UTF8.GetString(ms.GetBuffer());

s = s.Trim();
s = s.Replace("\0", String.Empty);

xml = new XmlDocument();
xml.LoadXml(s);

By the way, I get the same error when keep everything in the MemoryStream
and make the statement xml.Load(ms). I see no “stream visualizer” for
debugging purposes.