CONNECT Edition 10.08.00.51 (Update-8)
The requirement is to export the design files to the local directory in a locked state & import it back to the PW explorer. During this, no other user can access that file & can only be imported back by the user who had exported it. This wiki article explains the steps to do so.
If above problem still persists, then please create a Service Request and contact the Bentley Product Advantage group. Please include a list of all relevant details to get in depth analysis for a solution or workaround