Hi Elham,
1. Go to transaction PPOSA_BBP and search for the user XXX . Check if the user exist in the SRM org structure. If the usr doesn`t exist, replicate the user from HR system or create him in SRM.
If you are replicating from the HR system via IDOC, execute the IDOC procesing program in SRM.
2. If the user exist Click on the user and in the right hand side the user details will be displayed, in that check if there is only one line with US xxxx.
3. Ideally every user sould have three lines US XXXX, CP and S.
4. If CP number and S ( position ) is not available for a user in the org structure you will be get that error.
5. Run the Users_gen transaction -> Copy user and employee data from template->create users from existing su01 users--> execute action-> enter the org ID ->continue choose the user and continue.
6. Now CP and position would have got created in the Org structure.
Check if you still have the same error.
Regards,
Suresh