DataSource &1 from source system &2 could not be activated

What causes this issue?

BW has attempted to activate the DataSource remotely from Business
Content. This was not successful.
Automatic activation is only available as of Plug-In 2000(-A). In
addition, the DataSource must exist in the source system of the D-
version, and the RFC connection to the source systsm must be correctly
maintained.

System Response

The DataSource could not be activated from Business Content.

How to fix this error?

Ensure that the above conditions are fulfilled. If you are unable to do
this, call up the <LS>Customizing of Extractors</> from the
Administrator Workbench- Modelling for a Source System. You then reach
the source system IMG, where you can activate the DataSource manually.

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.