Hello,
I'm new to programming and I'm trying pull serial data from my Arduino into Processing.  The data is coming from an accelerometer.  I have installed "Standard Firmata" on the Arduino but when I try to run my processing program, I'm getting the above mentioned error message.  Any help would be much appreciated.  Here's my code:

1. import processing.serial.*;
   Serial port;
   
   int serialCount = 3;
   int sensorPinX = 2;
   int sensorPinY = 3;
   int sensorPinZ = 4;
   int[] xArray = new int [8]; //smoothing can adjust numbers from 0 - 10 or highger
   int[] yArray = new int [8];
   int[] zArray = new int [8];
   char DELIM = ',';
   int length;
   
   void setup() {
    
     String arduinoPort = Serial.list()[0];
     port = new Serial(this, arduinoPort, 9600);
     }
   
   void draw() {
     int i;
     int xpos;
     int ypos;
     int zpos;
   
     addEntry(xpos,xArray);
     ypos = analogRead(sensorPinY);
     addEntry(ypos,yArray);
     zpos = analogRead(sensorPinZ);
     addEntry(zpos,zArray);
   
     Serial.print(xpos);
     Serial.print(" ");
     Serial.print(ypos);
     Serial.print(" ");
     Serial.println(zpos);
     delay(100);
   }
   
   int getAverage(int valueArray []){
     int i;
     int sum = 0;
     int average;
     for (i=0;i<length;i++) {
       sum += valueArray[i];
       }
       average = sum/length;
       return average;
     }
   
   void addEntry(int value, int valueArray []) {
     int i;
     for (i=0;i<length-1;i++) {
       valueArray[i]=valueArray[i+1];
       }
     valueArray[length-1] = value;
   }
    void serialEvent(Serial myPort) {
           String serialString = myPort.readStringUntil('\n');
           if (serialString != null) {
             String[] numbers = split(serialString, DELIM);
             if (numbers.length == sensorCount) {
               addEntry(numbers[2],xArray); //pin numbers inside braces
               addEntry(numbers[3],yArray);
               addEntry(numbers[4],zArray);
             }
           }      
         }