Watershed delineation error!

[Samar Mohamed]

Dear all,

I am facing a problem in my watershed delineation. The area is flat so I use a predefined watershed. After assigning the required shapefiles; DEM, watershed, channels, and subbasins, an error appeared. A window says that "circular drainage network from channel link 7. when I excluded this channel with its subbasin. The error continued to appear for another channel. Any help in that, please?!