• Error no.7 ,no cross sections exist in the database

    Dear all,
    Can anybody tells me what's the meanning of 'no cross sections exist in the database' when I simulate the whole program?
    I try to build up a river network and set the cross section of each river as the same because of no real data. But when I see the errors and try to insert the interpolated cross-section and changes the data of the different cross section, it still gets the errors. So could anyone know what's the reason of this situation and what I should do to fix it?
    Many thanks,
    Alison