Please open the Datastage Administrator and connect to the domain and you will see the projects listed. Click on the project and select Command button in the Projects tab. You will get a window as Command Prompt.
Type ds.tools in it and you will have 4 options displayed. Select the 4th option--> Administrator process/locks.
Select 4 -->List all locks (You will get all the locks, please not the PID number) Then select 7 option --> Clear locks held by a process. It would ask for the
PID no and after entering it the locks will be cleared.
Please wait for sometime and later you will be able to open the job in the Designer.