Can anyone please explain about these two different errors as shown in the screen capture.
The user notification in the image you provided references catch basins that don't have subsurface elements attached to them. When flow enters a catch basin it will then be subsurface flow. If a conduit is connected to the catch basin, then it can convey that subsurface flow. Without the conduit attached, the subsurface flow will have nowhere to go. This is why the message states that the captured subsurface flows are lost.
Bentley Technical Support
If there are conduits attached to these catch basins, they will need to connect to an outfall to be "valid".
Make sure there aren't any overlapping nodes that create a disconnection in the network.
You can use Network Navigator to locate elements that are disconnected from the outfall.
To do this:
1. Go to View > Navigator
2. Click the ">" icon > Network Trace > Find Disconnected
3. For the "Find Elements Disconnected From" input field, choose "Select..." > click on the outfall element > Click OK.
4. The Network Navigator dialog will then list all elements that are disconnected from that outfall.
5. Click the highlight icon in the Network Navigator dialog to highlight all of the returned elements.
This should make it easy to locate where the disconnection is in the model.
The Network Navigator, Network Review query "Orphaned Nodes" may help as well.
The following article was written for the different products, but it does a good job at explaining how to use the tool and includes a video demonstration.
Using Network Navigator
Actually I connect that catch basin with gutter.
Also, I have hard my hard time to figure out some error in my model. Can you please help me to figure out.
There is flow in my gutter but it is not coming out from outfall and seems lost from somewhere.
I also insert some fake catch basins with percent capture 0.001 to start my gutter somewhere like GU16, GU 17 etc.