If none of the above works for you, double check that you do in fact have the necessary permissions to launch the game. Some players have also reported simply logging out and back in as a fix, but again, we've always had to do a full restart. You might find you need to restart your router as well as the console if these methods don't work, but we have never needed to - a quick console reboot has always been enough. The purchase option should instead say 'Launch game,' so give that a click (just in case permission privileges need refreshing), then do the console restart as above after the error pops a second time. If it's something downloaded by a different user, click the 'See in store' button that pops up under the error message when you try and launch it. If the error occurs right after you download a game (this was especially common with Game Pass titles for us, notably ones we'd previously played or downloaded elsewhere), hold down the Home button and select the far-right option, 'Restart console.' This reboot is usually enough to get the system to rerun the permission check and find that since you literally just downloaded the game, you're probably entitled to play it. If you play across several Xbox devices and are still getting this error, there's a different but equally simple solution.

It's still worth setting up on what you consider your primary console, mind, since it lets any users access the games and apps you download, as well as allowing them to enjoy the benefits of your Xbox Live account such as online play and store discounts. Note that this can only be changed up to five times per year, so it won't help you if you're playing across multiple consoles regularly. To set this up, jump into the Settings and go to General > Personalisation > My home Xbox and activate it there. This essentially skips the permission check which causes the error for anything you download on your account to that console. If you only play on a single console, the easiest fix is to make that your home Xbox.

Xbox game pass app not signing in