Make sure those two lines are inside either the robotInit() method or the constructor
Code:
public void robotInit() {
chassis.setInvertedMotor(RobotDrive.MotorType.kFrontLeft, true);
chassis.setInvertedMotor(RobotDrive.MotorType.kRearLeft, true);
}
or
Code:
...
public RobotTemplate() {
compressor.start();
chassis.setInvertedMotor(RobotDrive.MotorType.kFrontLeft, true);
chassis.setInvertedMotor(RobotDrive.MotorType.kRearLeft, true);
}
...