Hi Ankit,
This Error could have occurred may be because ‘Load Balancing’ is set to ‘Yes’
To solve this issue
1. ‘double click’ on the system SID.
2. Click on ‘Maintain Destination’.
3. Select ‘Administration’ Tab and UNCHECK the ‘Destination not modifiable’.
4. Goto ‘Technical Settings’ tab and select ‘No’ as a ‘Load Balancing’ value.
5. Goto ‘Logon & Security’ and Enter Details of partner system.
6. Click on ‘Yes’. Then on ‘Save’.
7. Again ‘Check’ the ‘Destination not modifiable’. And Click on Save.
[Note: After Saving, Do not Press ‘Back’ Button to go back, Please enter ‘\n’ in command box. If you press back button all the changes are lost. ]
8. Again goto ‘SMT2’ and Check the ‘Single Status’ .
To Check whether transaction are running or not from source to partner system.
Double click on partner System and Click on ‘Transaction Call’. A pop-up window appears, Enter any transaction code and click on Continue. The transaction runs on ‘partner’ System.
Also make sure you have user in the destination system too.
Good luck!
Sunil B N