Hello, I am trying to work on a guitar neck model the instructions videos I am working with are from CNC Guitars the have what appears to be a pretty good instruction set for this. every thing seems to have been going well until I attempted to pierce a lie endpoint to a line on a different plane. The process; using Solidworks 2015 student/vet edition I have created a drawing of a guitar peg head on a plane then created a new plane the appropriate distance from the original than selected several lines and and selected convert entities to create a copy of the selected lines on the new plane, no problem. the reason for this is because the back of the peg head has come contours and the front is flat. on the new plane I add a new spline to represent the contour and attempt to pierce to a line on the back curve of a different plane ( per the instruction on the video.)I am getting the error "no intersection found for pierce point".  ( side note the video is using a much earlier version of Solidworks ( not sure which)) but every other function works in a similar fashion enough to get the other tasks completed. I have created some test files with simple squares and lines on separate planes and of course it works fine on the file that is not important. It appears to be obvious that I am doing wrong although this seems to be a simple function I am completely frustrated.  Any suggestions would be greatly appreciated

Dennis