Hello,

I am attempting to transfer code written from one Mac to another Mac.  This code works on one Mac, but not on the other.  I was not the original author of the code, and I have no idea where the error is.

This is the error:
java.lang.NullPointerException
    at processing.app.Library.getClassPath(Library.java:298)
    at processing.mode.java.JavaBuild.preprocess(JavaBuild.java:390)
    at processing.mode.java.JavaBuild.preprocess(JavaBuild.java:197)
    at processing.mode.java.JavaBuild.build(JavaBuild.java:156)
    at processing.mode.java.JavaBuild.build(JavaBuild.java:135)
    at processing.mode.java.JavaMode.handleRun(JavaMode.java:176)
    at processing.mode.java.JavaEditor$20.run(JavaEditor.java:481)
    at java.lang.Thread.run(Thread.java:655)

This is my code:
import processing.serial.*;
import controlP5.*;

static float PRIMING_MODE = 1.0;
static float TESTING_MODE = 2.0;

static int ACTIVATION_STATE_ACTIVE = 1;
static int ACTIVATION_STATE_INACTIVE = 2;

int PRIMING_THRESHOLD = 90;
int TESTING_THRESHOLD = 100;
int SERIAL_PORT = 0;
int PERCENT_ALLOWANCE_DEFAULT = 12;

int TOY_ACTIVATION_DURATION = 3000;


int ACTIVATION_STATE = ACTIVATION_STATE_INACTIVE;
int THRESHOLD = PRIMING_THRESHOLD;
int PERCENT_ALLOWANCE = 0;
int MAX_REACHED = 0;

float MODE = PRIMING_MODE;

int MIN_READING = 70;
int MAX_READING = 690;

float beginning_of_testing_mode = 0;

float temp_beginning_of_activate = 0;
float beginning_of_activate = 0;
float end_of_activate = 0;

Serial myPort;    // The serial port:
PFont myFont;     // The display font:
String inString;  // Input string from serial port:
int lf = 10;      // ASCII linefeed
int chartHeight = 180;
int chartWidth = 500;

boolean on = false;

ControlP5 controlP5;
Toggle active;
Textlabel debug;
Slider debugSlider;
Chart myChart;
RadioButton radioButton;
 
void setup() {
  size(600,300);
  smooth();
 

  myFont = loadFont("ArialMT-18.vlw");
  textFont(myFont, 18);
 
  println(Serial.list());

  myPort = new Serial(this, Serial.list()[SERIAL_PORT], 9600);
  myPort.bufferUntil(lf);
 
  controlP5 = new ControlP5(this);
 
  controlP5.begin(10, 10);
 
  debugSlider = controlP5.addSlider("debug", 0, 1024);
  debugSlider.setId(3);
  debugSlider.linebreak();
  debugSlider.setBroadcast(false);
 
  active = controlP5.addToggle("active");
  active.setMode(ControlP5.SWITCH);
  active.lock();
  active.addListener(new ControlListener() {
    public void controlEvent(ControlEvent theEvent) {
      myPort.write("1");
    }
  });
  active.setId(4);
 
  myChart = controlP5.addChart("chart", 10, 100, chartWidth, chartHeight);
  myChart.setColorBackground(0);
  myChart.addDataSet();
  myChart.addDataSet();
  myChart.setId(1);
 
  ChartDataSet pressureDataSet = myChart.getDataSet(0);
  pressureDataSet.setStrokeWeight(2);
  pressureDataSet.setColor(color(255,255,255));
 
  ChartDataSet thresholdDataSet = myChart.getDataSet(1);
  thresholdDataSet.setColor(color(255,0,0));
 
  ChartDataSet allowanceDataSet = myChart.getDataSet(2);
  allowanceDataSet.setColor(color(0,255,0));
 
  controlP5.end();
 
  radioButton = controlP5.addRadioButton("radioButton",500,10);
  radioButton.setColorForeground(color(120));
  radioButton.setColorActive(color(200));
  radioButton.setColorLabel(color(255));
  radioButton.setItemsPerRow(1);
  radioButton.setSpacingColumn(50);
  radioButton.setId(2);
  radioButton.setNoneSelectedAllowed(false);

  addToRadioButton(radioButton,"PRIMING",int(PRIMING_MODE));
  addToRadioButton(radioButton,"TESTING",int(TESTING_MODE));
 
  radioButton.activate("PRIMING");
}
 
void draw() {
  background(0);
}

void addToRadioButton(RadioButton theRadioButton, final String theName, final int theValue ) {
  Toggle t = theRadioButton.addItem(theName,theValue);
  t.captionLabel().setColorBackground(color(80));
  t.captionLabel().style().movePadding(2,0,-1,2);
  t.captionLabel().style().moveMargin(-2,0,0,-3);
  t.captionLabel().style().backgroundWidth = 46;
  t.addListener(new ControlListener() {
    public void controlEvent(ControlEvent theEvent) {
      toggle_mode();
    }
  });
}
 
void serialEvent(Serial p) {
  if (on == true) {
    inString = p.readString();
    String[] tokens = split(trim(inString), "|");
    if (tokens.length < 2) return;
   
    // println(tokens);
   
    if (tokens[0].equals("reading")) {
      int value = int(tokens[1]);
      if (value > MAX_REACHED) {
        MAX_REACHED = value;
      }
      debugSlider.setValue(value);
      myChart.addFirst(0, map(value, MIN_READING, MAX_READING, 0, chartHeight));
      myChart.addFirst(2, map((THRESHOLD - (THRESHOLD * (PERCENT_ALLOWANCE/100.0))), MIN_READING, MAX_READING, 0, chartHeight));
      myChart.addFirst(1, map(THRESHOLD, MIN_READING, MAX_READING, 0, chartHeight));
      if (value > (THRESHOLD - (THRESHOLD * (PERCENT_ALLOWANCE/100.0))) ) {
       
        if (active.getState() == false) {
          ACTIVATION_STATE = ACTIVATION_STATE_ACTIVE;
          beginning_of_activate = millis() - beginning_of_testing_mode;
          temp_beginning_of_activate = millis();
          active.toggle();
          return;
        }
       
      } else {
       
        if (ACTIVATION_STATE == ACTIVATION_STATE_ACTIVE) {
          ACTIVATION_STATE = ACTIVATION_STATE_INACTIVE;
         
          if (MODE == TESTING_MODE) {
            end_of_activate = millis() - beginning_of_testing_mode;
            println("data point - [start: " + beginning_of_activate + "], [max: " + MAX_REACHED + "], [end: " + end_of_activate + "]");
           
            // reset threshold to next value
            // THRESHOLD = MAX_REACHED;
           
            // reset values for this breach
            // MAX_REACHED = 0;
            beginning_of_activate = 0;
            end_of_activate = 0;
          }
         
        }

        // if the toy is on, but it's dropped below threshold, and it's been more than TOY_ACTIVATION_DURATION, then disable toy
        if (active.getState() == true &&
            ACTIVATION_STATE == ACTIVATION_STATE_INACTIVE &&
            millis() - temp_beginning_of_activate > TOY_ACTIVATION_DURATION) {
          active.toggle();
          if (MODE == TESTING_MODE) {
            THRESHOLD = MAX_REACHED;
          }
          return;
        }
       
      }
     
    }
   
    myPort.write("2");
  }
}

void keyPressed() {
  if (key == CODED) {
    if (keyCode == UP) {
      toggle_on_off();
    }
  }
}

void toggle_on_off() {
  if (on == true) {
    on = false;
  } else {
    on = true;
    myPort.write("2");
  }
  println("toggling " + on);
}

void toggle_mode() {
  if (MODE == TESTING_MODE) {
    MODE = PRIMING_MODE;
    THRESHOLD = PRIMING_THRESHOLD;
    PERCENT_ALLOWANCE = 0;
  } else {
    beginning_of_testing_mode = millis();
    MODE = TESTING_MODE;
    THRESHOLD = TESTING_THRESHOLD;
    PERCENT_ALLOWANCE = PERCENT_ALLOWANCE_DEFAULT;
  }
 
  MAX_REACHED = 0;
 
  /*
  float f1[] = {};
  float f2[] = {};
  myChart.updateData(0, f1);
  myChart.updateData(1, f2);
  */
}

----------------------------
I'm hoping this is a simple bug, and that it's easy to spot!  I'm eternally grateful for any help anyone can offer.

Thanks.
Kayla