Hello SAP Experts,
An authority check for object S_RFCACL (expected to be assigned to the user in the target system) is performed in the target system while performing an RFC or HTTP communication between two ABAP systems using "Trusted System" for authentication.
The authorization checks fail because of insufficient authorization the "Trusted System" login attempt also fails.
An error message "You are not authorised to logon to the target system (error code 0)." is returned from caller side.
But in the target system, the Security Audit Logs shows successful login. Also, the login timestamp gets updated in the target system indicating a successful login.
The S_RFCACL authority check was performed after the (successful) authentication. But now the S_RFCACL check gets triggered while authentication process was going on, therefore, the entire authentication will also fail to result in a new error code: 1002.
When you will apply the correction in the target system you'll notice different behaviour as described above: