Related: https://forum.affinity.serif.com/index.php?/topic/37597-ad-export-persona-item-has-duplicate-paths/
Change the message of the error icon to the specific error: If the artboard was named twice the same, say e.g. "The Artboard/Path-Name is used multiple times". The actual message ("The Item has duplicate Paths") indicates Paths that are exactly the same (not only the name) and do overlap or such thing.
Greetings, Johannes