@Dave-
Sketchucation wouldn’t let me reply to your chat (error: you need 10 reputation to chat)…paying for losing my old account info.
I tried what you said, and still couldn't get the split tool to work. It has something to do with how my contour scene is set up? Do I need to drape my contour lines down onto a rectangle? In Layout that Layer always bring up the yellow triangle of doom, whenever I change something in the model and the update the model reference. Sometimes the contours lines then disappear in Layout for no good reason. Just now I changed something in my Existing Conditions scene and the yellow triangle is appearing related to that Layer. Auto render is on, and has been the whole time. Good grief, Layout continues to just school me. I brought in my initial viewport, then copied, locked the viewport, then chose new layer, and pasted to current layer…making sure to lock my viewports as I went.
I have the files uploaded to dropbox, is there another way I can dm you?
Thanks!