Question:
Why are some users, who have the required permissions, unable to access the Archived Documents tab in Vault?
Answer:
If Document Archiving is enabled in the Vault and a user with the permission to view the Archived Documents tab is unable to do so, then the user has a Read Only license.
By design, Read Only users are prevented from viewing the Archived Documents tab but can still access Archived Documents tab through Vault's Advanced Search menu.
Related Documentation:
Vault Archiving Documentation: Related Permissions