Unlock Audio
When PlayoutONE is playing an Audio file, this file is marked as locked, this prevents any changes being made to this cart whilst it's being played, this lock is automatically cleared after the cart has finished playing.
In some instances, this lock might not be cleared, if you open a cart and it states "This cart is locked and cannot be edited". First of all, check to ensure that the cart is indeed not playing, and if that's the case, right-click on the cart and choose Unlock Audio, this will then clear the mark against that file to say it's locked