hello everyone. I had this issue several times. though it seems everything is correct. the curves are connected
but still I can't get the results. I even did the same method from Youtube but still I couldn't proceed.
I don't understand the message either. But the inputs shown in the attached image will give you a twisted surface. As Mech@sharma said, click the red arrow I'm pointing to to flip it to match the direction of the circled arrow.