At approximately 2022-12-07 21:44 UTC the service was updated with a change to the internal format of the player session ticket. This session ticket is returned from player login APIs and is used for authenticating requests to Client APIs. The service update also included a similar change to the internal format of the server authorization ticket used in Classic Matchmaking APIs. At approximately 2022-12-08 04:45 UTC the service update was rolled-back to revert to the previous ticket formats, after some customers notified us that their titles had dependencies on the previous format.
The format of the player session and server authorization tickets is not publicly documented, and the format and length are subject to change at any time. Therefore, we recommend that titles treat these tickets as opaque strings and do not attempt to parse them or make assumptions about their length.
We plan to deploy the ticket format change again in the coming weeks (date TBD), after the affected customers have had an opportunity to update their titles. If your title was affected by the session ticket change, please contact support to coordinate the change in order to avoid further disruptions to your title.