Hey @ws696201 , I am in the middle of the exam and am having this exact issue. Did you ever sort this out? Formula updates won't work (same error message you got), and I cannot add the top level item "All Roles" for the same reason you couldn't - " 'All Roles' is not valid for the name of the top level item of Roles. 'All Roles' clashes with the name of an existing List Member. "
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