credentials are wrong

If you have 2FA setup on your account you'll need to setup an app password to access your account on the 360.

https://support.microsoft.com/en-us/help/12409/microsoft-account-app-passwords-and-two-step-verification

Hello AControllerUser,

Thank you for posting on the Xbox forums. We understand that you are unable to access the Xbox 360 profile for your Microsoft account. We recommend deleting your Xbox 360 profile information on your Xbox One and downloading it back to the console. There
are specific steps that need to be taken to complete this process. We'll provide the list of steps. Be sure to let us know the result
AControllerUser!

How to remove your profile:

1. Launch an Xbox 360 game on your Xbox One
2. Wait until you get past the Xbox logo and press the View and
   Menu buttons at the same time to pull up the Xbox 360 guide
3. Go to Settings and look for storage settings
4. Select profiles
5. Delete your profile(Profile only) Do not delete profile and items

How to download your profile:

1. Once your profile has been removed, press the View and
   Menu buttons at the same time to pull up the Xbox 360 guide
2. Select download profile

Hey there

Thanks for visiting the forums with this issue

I'm afraid this seems to be a problem you need help with from xbox support they can help with this issue

You can reach them at

https://support.xbox.com/en-GB/contact-us

You must not understand, i can't download my profile in the first place, due to an error with credentials apparently when they all work. Error code 8015190A

I had that ages ago so I just stopped using that account and started from scratch, is your email like *** Die E-Mail-Adresse wurde aus Datenschutzgründen entfernt. ***, you may have a out of place letter like *** Die E-Mail-Adresse wurde aus Datenschutzgründen entfernt. *** when you made the account because my account was @hitmail.co.uk so the I instead of O and
I got the same error mate just hoped that helped.