You have not configured the RFC destination for CRM system; see long text

What causes this issue?

You have not configured the RFC destination for the connected CRM
system.

How to fix this error?

Contact your system administrator.

Procedure for System Administrators

Call transaction SE16.
Enter the table <LB>CRMRFCPAR</> in the input field.
Create an entry for the user CRM: <LS>CONSUMER</> = <LB>CRM</>
In the <LS>RFCDEST </>field, enter the RFC destination for the connected
CRM system.

Error message extract from SAP system. Copyright SAP SE.