Hi Maha
Please, follow the next steps:
816926 - Error when attempting to import BPC transport request on the target system
Resolution
- Run SM59 transaction in BW,
- Scroll down the "ABAP Connections"node and double-click on the proper RFC connection (the one used by BPC),
- Go to "Logon & Security" tab,
- Type "Ctrl + F1" key combination on the keyboard,
- In the "Password" field, re-enter the corresponding password of the BW service user,
- Click on "Save" button:
Best Regards,
Juan Pablo Ch.