Changes not allowed in this system (central user administration active)

What causes this issue?

You have attempted to change user data. This system is part of a system
infrastructure that uses central user maintenance. The settings here
specify that certain data is allowed to be maintained either only in
the central system or only in a dependent system. According to these
settings, this action is not permitted in this system.

System Response

No data is changed.

How to fix this error?

If you are logged on to a dependent system, make the changes in the
central system. If you are logged on to the central system, make the
changes in the dependent systems.

Error message extract from SAP system. Copyright SAP SE.