I'd like to add some constructive information.
I am indeed having the same issue.
I was in the GPP (Game Preview Program), bought in at the end of August last year.
This morning after downloading and applying the update, got the error message mentioned in the topic post.
-Logged into different Gamertag on same Xbox system, and it let me in. Of course I had no save data with that account so it was basically like starting new.
-Afterwards logged back into my main Gamertag, issue persists.
-Tried 'closing' (full quit from Xbox dashboard) the game and restarting, issue persists.
-Tried logging back in with second Gamertag again, making into the game one again, then quitting to Main Menu and then switching back to main Gamertag. Issue persists.
-Tried full heavy restart of Xbox console, issue persists.
-Xbox Marketplace enabled me (perhaps erroneously) to purchase the game 'again' with main Gamertag. Did so... Issue persists.
-Finally uninstalled all instances of Elite Dangerous from console, then reinstalled all instances. Issue persists.
I heard that clearing the Xbox cache had worked for someone, but I have not tried it myself, instead came here for help.
Hopefully presenting my troubleshooting can help with working towards the solution...
-DHX
Gamertag: DHX