Unable to sign in after you change your pass code or recover your account
If you encounter this issue, you most likely are attempting to sign in using an account that was disconnected during the last pass code change or account recovery. Either copy the account from the original Xbox (or Xbox Memory Unit) that participated in the pass code change or account recovery, or use account recovery to re-create a valid copy of the account. Keep in mind that if you perform account recovery at this time, all currently disconnected accounts will once again become invalid.