I have tested my XSL in a browser - checked by adding the following line to the top fo the Show  XML output and saving it as a file

<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="MYXSLFILE.xsl"?>

If I open xml it correctly transforms and works fine in the browser.

I have uploaded my xsl file to DNN and selected it as an XML Visulizer.

When I open the DNN page the values from the XML file are correctly inserted into the output but the HTML markup from the XSL file is visible - i.e. its encoded.

E.g.

<b><xsl:value-of select="Name"/></b> in XSL Outputs <b>SomeName</b> instead of SomeName

The first few lines of my xsl file are

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" version="1.0" indent="yes" omit-xml-declaration="yes"/>

 Any ideas?

Ryan, I can't reproduce your issue, however here some sample code:

SQL Query:

Select top 2 * from users

Returns

<?xml version="1.0" encoding="utf-8" ?>
<DocumentElement>
<QueryResults>
<UserID>1</UserID>
<Username>host</Username>
<FirstName>SuperUser</FirstName>
<LastName>Account</LastName>
<IsSuperUser>true</IsSuperUser>
<Email>host</Email>
<DisplayName>SuperUser Account</DisplayName>
<UpdatePassword>true</UpdatePassword>
</QueryResults>
<QueryResults>
<UserID>2</UserID>
<Username>admin</Username>
<FirstName>Administrator</FirstName>
<LastName>Account</LastName>
<IsSuperUser>false</IsSuperUser>
<Email>admin@localhost</Email>
<DisplayName>Administrator Account</DisplayName>
<UpdatePassword>true</UpdatePassword>
</QueryResults>
</DocumentElement>

Stylesheet:

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match ="DocumentElement/QueryResults">
<xsl:value-of select ="DisplayName"/>
<br/>
</xsl:template>
</xsl:stylesheet>

Renders to:

<?xml version="1.0" encoding="utf-8"?>
SuperUser Account<br />
Administrator Account<br />

Shown correctly as:

SuperUser Account
Administrator Account

Now I know what to look for its in the issue db and has been corrected already for v5

http://support.dotnetnuke.com/issue/ViewIssue.aspx?p=0&id=6514