Changed my gamertag on Xbox One, now I can't play?

Games Other Halo
1

As the title says, I changed my gamertag on Xbox One, and then tried to play Reach, only to be met with the “Not Signed In” notification. I chose my profile, but it showed my old gamertag, and by selecting it, was only met with this:
“Sorry, this profike can’t connrct to Xbox Live on this console. To fix it, download again.”
Uninstalled and reinstalled Reach, problem persists.

Any helpful tips?

2

You have re-download your account.

3

When you are on the menu compare a profile select chose your new and download your old profile transfer