An identical aggregate to '&1' already exists

What causes this issue?

An aggregate (called '&V1&') that has the same characteristics as
aggregate '&V2&' already exists and it is not advisable to create
several aggregates with identical characteristics.

System Response

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

How to fix this error?

Delete or change one of the two aggregates.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.