Start with the right checks.
The message can reflect the signed in account, subscription status or an installation issue. It does not by itself identify which product you need.
What to do next.
Record the exact message and application version.
Check which account is signed into the app and which account owns the subscription.
For a business subscription, ask the administrator to confirm the assigned license and its application entitlement.
Use Microsoft’s activation troubleshooter on the affected Windows PC if appropriate.
Check the result.
Confirm that the application reports the intended license and that editing works. Check the exact product name rather than only the Microsoft 365 label.
Stop and get help if…
Multiple installations or accounts are involved, the subscription cannot be verified or repair would remove software. Microsoft licenses and DeltaBind Email Care are separate charges.