It looks like this is part of another multi-thread of troubleshooting. I’d recommend keeping it all together in one location.
That being said, you’re feeding a list of Lines into the X&Y inputs of the Point node. You need to be feeding numbers into those inputs, not Lines.
can I have a graphe?
No, because I genuinely don’t know what you’re trying to do with this graph. I took a peek in the other topic - It looks like you were working on learning how to generate surfaces? I don’t know what you intend the ‘next step’ to be here once you have a compiled list of lines, or what you’re looking for in a final result.