From our website the Game Content menu links to The NecroMech Dossier, Stitched!, etc.
You must subscribe to The NecroMech Dossier - Core Gameplay Manual FIRST.
Otherwise you will see an "As this is not the latest issue you will not get it with subscription" warning if you attempt to subscribe via all other content.
Once the link has been updated this warning will no longer appear and you will have full access.