Ok, this took forever to track down. If you have a field that is in a field collection (provided by the field_collection module) then you have to turn on the "Administer Field Collections" permission for the roles that need to be able to download the files that are under private_files_download_permissions ACL. This is a security flaw since I don't want the role selected to be able to modify the fields at all.
Closed: outdated
2.0
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