XML Append Child - error 2603

[FabioBone]

I need to append a child to a XML structure from another XML structure. Labview 2011 pop-up the error 2603:

Internet Toolkit:  Node was used in a different document than the one that created it (that doesn't support it)
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LabVIEW:  Used a node in a document other than the one that created the node, and which does not support the node.

I used the property append chils as well as in the figure I report. What is wrong?

Thanks

[TroyK]

I can see two ways to do it...

TIP: to get the XML function to work properly you MUST ALWAYS close off ALL opened nodes.

If you have missed/forgotten to close off a node, shut down LabVIEW completely to release the open reference.