Aggregate &1 deactivated (uses deleted or time-dependent attribute)

What causes this issue?

A navigation attribute that is used in aggregate &V1& has been deleted
or changed to 'time-dependent'.

System Response

Aggregate &V1& is deactivated. Time-dependent navigation attributes can
not be used in aggregates.

How to fix this error?

Cancel the changes in the attribute or adjust the aggregate to the
characteristic after activation.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.