Name of DataSource &1 does not start with standard prefix '&2'

What causes this issue?

The name of DataSource '&V1&' does not have the current predefined
prefix '&V2&' for APO DataSources. As of BW* 3.0 only prefix '&V2&' is
permitted for APO DataSources. This means that you cannot use the
DataSource in a BW 3.0 system (or more recent system). It is also
advisable to update the name of the DataSource for compatibility with
possible future APO release upgrades.
* Business Information Warehouse

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 the old DataSource and regenerate it. All new DataSources are
generated with the prefix '&V2&' by default.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.