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Purge occurrences can be found under the dRofus tab in Revit.
You will then be presented with an overview of the existing occurrences in dRofus with no corresponding family type in Revit.
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To prevent this from happening, please follow the steps explained here: Model Name/wiki/spaces/WA/pages/1318359510
Tip: You may want to remove the Item as well from the items module in dRofus.
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