When the Ask user option is selected in the Talend Administration Center web application, you get prompted to put a lock on any item you open in the Studio.
If you want to edit the item you are opening, click OK to put a lock on it. The item becomes read-only for other users like in the default mode.
When closing or saving the item, you get prompted again to unlock it. If you are complete with the changes, then click OK to remove the lock and allow other users to lock it if needed.
If you do not need to open the item in edition mode (lock) then click No when prompted to open it in read-only mode.