A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hello Douglas,
You should not need to change your Microsoft 365 Family plan or become an administrator. Family subscriptions are managed through a personal Microsoft account, not through an organization’s admin center.
This message may appear if Excel is still detecting an old work or school account. In Excel, select File > Account, sign out of every account, close all Office apps, then reopen Excel and sign in only with the personal Microsoft account that owns or receives the Family subscription.
Also check Windows Settings > Accounts > Access work or school. If an old organization account is listed and you no longer use it, disconnect it.
Finally, return to Excel > File > Account and select Update License, then restart Excel. Also install any available Office updates.
If the issue continues, open Credential Manager > Windows Credentials and remove entries related to Microsoft Office, such as credentials containing Office16. Restart the computer, reopen Excel, and sign in only with the personal Microsoft account associated with the Microsoft 365 Family subscription.
As a temporary workaround, test Excel for the web while troubleshooting the desktop app.