Ref T13484. If you load a subproject S which has a mangled/invalid parentPath, the query currently tries to execute an empty edge query and fatals.
Instead, we want to deny-by-default in the policy layer but not fail the query. The subproject should become restricted but not fatal anything related to it.
See T13484 for a future refinement where we could identify "broken / data integrity issue" objects explicilty.