Changed Free GamerTag and now I can't Download/Sign in with my Profile in my 360

I'm getting error code 80151006. This happened when I changed my gamertag on my new 360. My old gamertag and profile downloaded just fine on the new console but now that I changed it I can't download it. I've also tried to download my profile with my new
gamertag on my old console, it also will not download and I get the same error code.

I can't sign in to Xbox Live after I changed my Gamertag. When I tried to download the profile I got this error code 80151006. My free bundle Xbox game is also downloaded in that account. Please help. THanks...

Hello,

This is a randomly generated gamertag. Since you've logged into Xbox.com with the e-mail address it's given you a randomly generated gamertag. There's no way to remove the gamertag from the e-mail now. You can however, change the gamertag to whatever you'd
like once for free.

Just download this profile onto the Xbox 360 console and follow the instructions below:

Download Profile:

Push the middle button on your XBOX 360 controller.

Select Download Profile.

If you don't see Download Profile, then press X on your Xbox 360 controller to sign out of the current account.

Once you've done that, please follow the instructions below to change the gamertag:

1. On your console, sign in using the Xbox LIVE gamertag or Zune tag that you want to change.
   
   
2. Go to Social, and then select your gamertag.
   
   
3. Select Change Gamertag.
   
   
4. Note the Price of the change (it will be free the first time you change it), and do one of the following:
   
   • Select Enter New Gamertag.
   • Select Get Suggestions to view possible gamertags.
     
     
5. Once you enter or select a new gamertag, select Yes, use this gamertag.
   

I recently changed my gamertag on xbox one and made a longer password now when I go to play a 360 backwards compatible game on xbox one it says I have to re download profile so my gamertag will change but my password for live is too long on 360

Each 360 account can be associated with a Live account.

Currently I have:

old 360 account -> associated with my Live account but with the old gamertag

new 360 account -> associated with my Live account but with the new gamertag

The new account got created when I downloaded my profile using my microsoft sign in. The old account was associated with the same microsoft sign in but it didn't recognize my gamertag change. Now it won't let me sign in to live because it asks for my microsoft
sign in details. I'm guessing the sign in fails because it's trying to find the microsoft account associated with the old gamertag.

I either need to somehow transfer my saves over to the new 360 account so I can upload them to the cloud, or I need someway for my Xbox to realize that my gamertag changed on the old account so I can sign into live again with that account.