Found it in FairPlay Streaming Programing Guide42800
This error code is returned when persistent key has expired. The server always
has an option to add a validity period for each key it issues for offline playback.
Once the validity period is over iOS will refuse to decrypt offline content protected
with such key and indicate the error with this error code.
It is up to the application developers to decide whether to request a new key from
the server or treat this error condition as a permanent expiry; for example, a
recorded sporting event must not be playable after 48 hours and no key renewal
is possible.
To use the best practice and achieve maximum flexibility, always send a keyrenewal request to the server and let the server decide whether to allow the
renewal.