Microsoft Account fail: broken URL for parent permission to child having XBOX live account...

I would contact Xbox Support, they're very helpful and I'm sure they should be able to help you out.

I checked the issue with Microsoft Account tech support, and they sent me back here.

On their end everything work as expected: my parent account and child account are properly connected, I see the child account under the parent account, can set the permissions for the child account.

But apparently the parent-child accounts relations are not propagated correctly to the Xbox LIVE system.

Hi Frost,

Thank you for posting on the Xbox forums. Unfortunately it is not possible to force a child account to become an adult account on Xbox Live. Changing the Microsoft Account profile age will not change the account and give adult permissions to the child account.
An adult account would need to be set up separately by the parent and add the child account to a Microsoft Family group and then manage the child account while logged into the parent account to allow adult permissions on a child account. A child account cannot
make any Xbox Live privacy settings without an adult account. If you already have an adult account, sign into
family.microsoft.com. For further instructions on how to set up a family group and then manage the child account's privacy settings, please read the following support articles:

• Add members to your family group
• Xbox One online safety and privacy settings for parents and kids

The link provided by tez bomb is helpful setting up content restrictions directly on the Xbox One console, after you've already set up your Microsoft
Family.

I hope this helps!

You need to have Xbox Live Gold or this problem is related to permission of your parents If your account is a child account

Problem:

You see the following error and message when you try to sign in to Xbox Live using a child account:

Before you can sign in here, you'll need to sign in at Xbox.com.

An adult will also need to sign in so they can give permission.

Code: 83118853

This means that the parent account must provide permission for each associated child account (under age 13) before the child can access Xbox Live

Solution:

To resolve this issue, have the child account sign in to Xbox.com. Then, when prompted, the parent account associated with the child account should sign in to Xbox.com and give permission for the child account to sign in to Xbox Live.

If you keep experiencing the problem, contact Xbox Support.