Adjustment of namespace role only in SAP-internal systems

What causes this issue?

The namespace roles should be set to the default setting in the SAP
internal systems.
The current SAP system is, however, not set as an SAP internal system.

System Response

The action was canceled: The namespace roles are not changed, in order
to prevent inconsistent namespace settings.

How to fix this error?

If it is an internal SAP system then inform your system administrator
about the inconsistency. Repeat the function after the SAP system has
been set up as an internal SAP system.
If it is not an internal SAP system then, after the upgrade or
processing after the installation of the SAP system (with Transaction
SE06), no further manual actions for adjusting the namespace roles are
necessary.

Error message extract from SAP system. Copyright SAP SE.