I had the same issue during the San Diego Competition.
Make sure all sensors that you are calling actually exist, it took me a while but I found that I was calling for a Sonic Sensor on Analog port 1 when it was on port 0.
I would just make a very simple program and seeing if that uploads
Code:
package org.usfirst.frc.team3647.robot;
import edu.wpi.first.wpilibj.BuiltInAccelerometer;
/**
* The VM is configured to automatically run this class, and to call the
* functions corresponding to each mode, as described in the IterativeRobot
* documentation. If you change the name of this class or the package after
* creating this project, you must also update the manifest file in the resource
* directory.
*/
public class Robot extends IterativeRobot {
private BuiltInAccelerometer accel = new BuiltInAccelerometer();
public void robotInit() {
}
/**
* This function is called periodically during autonomous
*/
public void autonomousInit(){
}
public void autonomousPeriodic() {
}
/**
* This function is called periodically during operator control
*/
public void teleopPeriodic() {
SmartDashboard.putData("Test", accel);
}
/**
* This function is called periodically during test mode
*/
public void testPeriodic() {
}
}