Hi,
I'm now following the muscle car course. I stuck at designing the rear car glass. I have attached the screenshot of the problem. Hopefully someone can help me.
Thanks.
You most certainly have double vertices there. You can select all and M to merge by distance.
You can tell real easy when you have double vertices by the orange line selection, when it doesn't extend by your edges, you have them doubled. Here's some pictures to illustrate that. See how my selection orange outline extends on the connecting edges.
But here when I have those vertices doubled, the orange outline doesn't go past the edges. You can see how the connecting edges remain black:
See how in your screenshot the orange selection stops abruptly and doesn't follow up the edges as it should. Meaning you have double vertices there.
Also you have a Ngons here:
