What version of Microsoft 365 apps are you using now?
Please go to one Office app, such as Word, click File > Account > Product Information, check the version name and share with me, such as Microsoft 365 Personal, Microsoft 365 Apps for enterprise.
Generally, to activate Microsoft 365 apps, we may go to one app, click File > Account > Product Information, login your licensed account. Does this error message pop up after you sign in account in Office app?
- If yes, please right click one Office app icon, run as administrator, to check this issue.
Use the Microsoft Support and Recovery Assistant for help.
Besides, please go to Office 365 portal, check whether you could download the Office. If you could download the Office, please uninstall the existing one and reinstall it. - If not, after what operation did this error message appear? Did you login Microsoft 365 admin center?
The error message would be shown when you log into Microsoft 365 admin center but you do not have admin permission. Under this case, please contact your organization's global administrator for help.
If you are already have admin permission, it's better to switch broswer, such as IE.
In addition, clear the cache of browser.
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