Changing to manual mode causes NullPointerException

Pressing the manual radio button after the simulation has started, whether or not the simulation is running or paused, causes the following error:
Exception in thread "Thread-2" java.lang.NullPointerException
    at DataLayer.CTC.CTC.setSwitch(CTC.java:620)
    at DataLayer.NSE.runAutomatic(NSE.java:197)
    at DataLayer.NSE.run(NSE.java:140)
    at java.lang.Thread.run(Thread.java:744)
