Cross - bad After selecting the network or site layer for processing I don't see the FID or OBJECTID fields as options in the Polyline\Site ID parameter?

Tick - good These fields have been deliberately exclude from the list as they can cause some tools used by RivEX to function in unexpected ways. You need to have another field which is a unique numeric (integer) field for your river network or site layer. RivEX will build such a field and name it RivID when you run the Extract Topology tool.