I am trying to create a polygon feature from an enclosed line feature using the Geometry Tool: Lines to Polygons. When I do this, I get several spikes with the newly created polygon. I then run the "Check Geometry Validity" tool and it notes that I have about seven duplicate nodes. I am trying to delete the duplicate node using the Edit tools: Node Tool, select the node, but have not been successful with deleting the extra (or duplicate) node. I was told to use Fn + Delete on the keyboard (Mac OS), but nothing seems to happen. Please tell me the best way to get rid of these duplicate nodes.