In your code, there is nothing in the Knee event. You have the output terminals set to "Use default if unwired." This will cause a problem because the default is a blank string. Perhpas you intend to put something in the Knee event but haven't done so yet.
Put the Timeout case back. Add a boolean to each case, Timeout boolean will be false, the other events that send out valid path data will have a true. Then put the build path stuff inside a case structure inside the true case (nothing in the false case) with the boolean wired to the case selector. When Timeout occurs, the build path will not execute. When an event that sends out path info happens, the true boolean will cause the build path stuff to execute.
