Ask for permission - You'll need to ask an adult in your family if you can use: Windows Shell Experience

Here is an item on Microsoft's Feedback Hub with 52 votes and an official response:

"Microsoft Family Features dialog unexpectedly appeared stating I need permission to use Windows Shell Experience"

https://aka.ms/AA4qaiv

They've been 'looking into [it]' for over 6 months and still not fixed it. Nor did the Spring update. Very disappointing.

It has been 12 months I believe, this thread was started at the beginning of July last year but if you search there are multiple reports appearing from April 2018 when the bug was introduced through the Windows 10 update cycle. Very poor that the issue has not been resolved given the volume of users impacted and the visibility across multiple forums with exactly the same issue.

We have three PCs and two laptops in our home, with two adults and two children all part of a "Family" and on shared Office 365 subscription. Both adults (administrators) get this message when logging into any of the devices, and one of our children always gets a message to say that the account needs setting up properly and therefore cannot report on usage. I've followed all instructions regarding setting the child accounts up properly, and all is set as suggested by Microsoft, but still getting error messages. I've tried switching off all child features (screen time limits, reporting, etc.) but still getting same error messages. Also still getting pointless weekly "report" emails saying it can't report because something wrong in account setup, even though I have switched off the email report feature.

This "Family" feature actually worked when first introduced back in Windows 8 but over time it has gradually broken down to the point where I have effectively switched all features off, and we still all get plagued with these error messages on boot up and weekly emails telling us there is a problem. I have reported it to Microsoft through the Feedback Hub with detailed description, logs and screenshots, and never once had a response from them.

If it were not for the Office 265 subscription, I would probably delete all accounts and start them again without the "family" setup. I've long since given up hope of a fix from Microsoft. They are just not very interested.

Absolutely agree with mjfuller44.  The family features are now a mess (it's even problematic on our old XBox360 now, too, as well as Windows.......)