Problem with different items with identical sorting numbers

  • Hi, can someone answer to me - what is wrong with project or other it parts, when preparing machine control files, often I am geting this problem:
    ''In the selected group of objects, there are different items with identical sorting numbers. Please make a different selection.''
    Of course I am doing new sorting (SOMETIMES FEW TIMES), but that not helps???
    The last action was today with simple roof: there was details 94 psc., but 6 files was not enought...

    Vilmantas Liutkus
    Constructor engineer
    Roof constructions, timber frame - shield houses