Please use the update notification system to report a game patch, update or to report that the trainer may not be working with the latest version of the game. If 3 or more reports have been filed, consider BOOSTING the priority of this title for a faster turnaround on the updated trainer.
OK nvm, just downloaded the free DLC and then the game auto-updated after which the trainer recognize it with no problem. I never had this issue before but I'm glad it was a Steam version problem and not the trainer, so the staff can chill in peace and ignore the update request. Regards.