No Permission to Manage Attachment Versions
Even if an admin has 100% permissions, they will not be able to manipulate the attachment history of an attachment with multiple edits.
Fixed in the next release. The permissions for attachment edits were still using the keys from a pre-Alpha release when trying to find the corresponding attachment record, rather than the current keys. This is not a security risk (which would have allowed users to modify attachment history if they had permission to modify the page history of a page with the matching key) since Gamma 4. Even so, the user would have needed regular history modification permissions anyway in order to exploit it, so I would not consider this worthy of a Patch Level release.