I attended the Virtual User Group conference on 1/12 and created the dataflow shared by John Stevens in our instance. Incredibly helpful! However, it revealed a number of pages and cards with no 'Display Name' (owner). Within the admin section, I am not able to find the pages or the cards using the filters. When I search for pages/cards with no owner, I don't have any. I've isolated this down to 2 User ID's that are not in the 'People' dataset.
If I can't find the pages/cards that are identified, how do I remove them?