So, I bought the Season pass when the game launched, and have been playing regularly since day 1. The season pass has been working as intended all the way through The Dark Below. As far as I can remember, I was not required to download anything else. Now it seems my Season Pass is no longer valid. It says on my PS4 that it IS in fact installed, but I do not have access to anything related to The Dark Below (I first noticed it when trying to ride the Tumbler sparrow) No obvious options are available to me. There isn't an option to re-install the Season Pass as far as I can tell. Only option I can see, which shouldn't be the case, would be for me to Download The Dark Below (the PS Store does list this as a free download, but I haven't needed any extra downloads to use my expansion prior to this).