Please post the URL to the gallery so that we can take a look.
In the meantime, please see this FAQ regarding the 'Gallery XML Not Found.' message: http://simpleviewer.net/simpleviewer/su … #trouble_6

If following the embedding instructions here: http://simpleviewer.net/simpleviewer/su … html#embed
... then all the contents of the gallery folder should be in the same directory as the HTML document into which the gallery is being embedded.
Your gallery's XML file looks to be in the correct location and your gallery is displayed OK by the Mobile Player but not by the Flash Player, which displays the 'Gallery XML Not Found' message.
Try using a relative path to the 'simpleviewer.js' file. You could also try explicitly specifying the path to the 'gallery.xml' file via the galleryURL option.
If implementing both of the above suggestions at once, then your embedding code would become:

<!--START SIMPLEVIEWER EMBED.-->
<script type="text/javascript" src="svcore/js/simpleviewer.js"></script>
<script type="text/javascript">
var flashvars={};
flashvars.galleryURL="gallery.xml";
simpleviewer.ready(function () {
simpleviewer.load("sv-container", "100%", "100%", "transparent", true, flashvars);
});
</script>
<div id="sv-container"></div>
<!-- END SIMPLEVIEWER EMBED -->

Hi,

The problem was that the html page base was referring to the old location of the site,

After removing the base tag from the header everything is working fine.

Thank you for your help, I am very impressed with the support

Kind Regards