Reference Field on the PO Line Context Sensitive DFF is throwing an error

Summary:

We are trying to create a Context Sensitive DFF based on Category Field on PO line, so we need to default context sensitive dff to the category name selected on PO Line so that other fields will be showed based on that. But when we put Reference Field as CategoryID, it is throwing error that it is not valid. Did anyone had success with reference field in DFFs?

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