Operating concern &1 may only be activated

What causes this issue?

It is not permitted to change cross-client Customizing settings in the
entire system or in the client. Operating concern "&V1&" can only be
reactivated.

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?

If you want to change the operating concern, you need to change the
settings for the client. To do this, choose <ZH>Tools -> Administration
-> Administration -> Client administration -> Client maintenance</> in
the SAP menu.
Alternatively, you can reset the global system change option (SE06).
You need to make it possible to change the Customizing for cross-client
objects from within the client.
You also need to make it possible to change the client-independent
Customizing settings for the system change option from within the
global settings.

Error message extract from SAP system. Copyright SAP SE.