I’m using sketchup web. Reached a point again that I don’t know what I’ve done to cause the problem or how to fix it.
I’ve attached two images. The first shows the model that has two lines. I don’t know why the lines are there. Don’t recall drawing a rectangle. The face of this side of the model should be clear of those lines.
If I select one of the lines and delete it, then the face of the model between the two lines is also deleted. How can I delete the lines without deleting that surface area between the lines.
That would imply that the small face under the hole is not in the same plane as the larger faces on either side. Might be that you can use Push/Pull to bring the face out to flush or maybe the Move tool. Impossible to say exactly what the fix is without seeing the .skp file, though.
What is it that you’re modeling? Likely there’s a different approach that would eliminate the need to even have edges there to erase.
If you don’t care you can use the eraser and tap shift before erasing the edges, that won’t solve the coplanar issue but it will hide the edges and they won’t be visible unless you turn on hidden geometry. If you share the file any of us could give you a better solution though.