No password is maintained for RFC destination &

What causes this issue?

No password is maintained for the specified RFC Destination &V1&, but
one is needed to make a remote client copy.

Procedure for System Administrators

You can maintain the RFC destination in the menu 'Goto -> RFC
Destinations' (transaction SM59). If you do not want to specify a
password, you can setup a <ZK>Trusted System</> connection (RFC Single
Login). There must already be an appropriate user in the target client.
You must be able to open a session in the source client directly with
the 'Remote Login' pushbutton (Exception: the user in the source client
has the user type <ZK>Communication</>). <ZH>No logon screen </> which
prompts for the user must appear. Only then can you use the RFC
destination for a client copy.

Error message extract from SAP system. Copyright SAP SE.