I was playing with creating objects on a spline (following the Dominoes.blend example file) Something I did crashed blender. I reopened the file and I can no longer connect the purple spline socket to a purple spline socket. ??? I tried closing blender and starting from a new file. I opened the dominoes file and added new nodes (spline from object, get spline length) and was unable to connect the purple sockets.
What does it mean when a socket is faded (transparent)?