Compiler error with SevenSeg library and tone() function

:confused: :confused:
I want to control a countdown timer which when the time ends plays a buzzer.
When I use the SevenSeg Library with the tone() function in the same sketch I get an error.

Here is my code:

#include <TonePlayer.h>

//Library
#include "SevenSeg.h"

//Seven Seg
SevenSeg disp (10,9,8,7,6,11,12); //Defines the segments A-G: SevenSeg(A, B, C, D, E, F, G);
const int numOfDigits =2;       //number of 7 segments
int digitPins [numOfDigits]={4,5};  //CC(or CA) pins of segment

const int buzzer = A2; 

//Constants
const int startBT = 2;
const int changeBT = 3;
const int setBT = 13;
const int dotPoint1=A0; //left digit
const int dotPoint2=A1; //right digit


//Variables
String number="00";
int digit1=0;
int digit2=0;
int start, change, set;
int setPoint=0;
int countdown;

//Useful flags
boolean countFlag=false;

void setup()
{
  pinMode (buzzer,OUTPUT);
  pinMode(startBT, INPUT_PULLUP);
  pinMode(changeBT, INPUT_PULLUP);
  pinMode(setBT, INPUT_PULLUP);
  pinMode(dotPoint1, OUTPUT);
  pinMode(dotPoint2, OUTPUT);
  //Defines the number of digits to be "numOfDigits" and the digit pins to be the elements of the array "digitPins"
  disp.setDigitPins ( numOfDigits , digitPins );
  //Only for common cathode 7segments
  disp.setCommonCathode();
  //Control brightness (values 0-100);
  disp.setDutyCycle(60);
  disp.setTimer(2);
    disp.startTimer(); 
}

void loop()
{
  //Read buttons state
  start = digitalRead(startBT);
  change = digitalRead(changeBT);
  set = digitalRead(setBT);

  if (set == LOW && !countFlag){
    delay(500);
    if (setPoint<2){
      setPoint++;
    }
    else{
      setPoint=0;
    }
  }
  
  //Start counting...
  if (start == LOW && setPoint==0
  ){
    delay(500);
    if (!countFlag){
      countFlag=true;
      countdown = number.toInt();
    }
    else{
      countFlag=false;
    }
  }
  if (change == LOW && setPoint == 1 && !countFlag){
    delay(500);
    if (digit1<9){
      digit1++;
    }
    else{
      digit1=0; 
    }
    number=String(digit2) + String(digit1);
  }
  if (change == LOW && setPoint == 2 && !countFlag){
    delay(500);
    if (digit2<9){
      digit2++;
    }
    else{
      digit2=0; 
    }
    number=String(digit2) + String(digit1);
  }
  //Control dot points
  if (setPoint==0){
    digitalWrite(dotPoint1,LOW);
    digitalWrite(dotPoint2,LOW);
  }
  else if (setPoint==1){
    digitalWrite(dotPoint1,HIGH);
    digitalWrite(dotPoint2,LOW);
  }
  else if (setPoint==2){
    digitalWrite(dotPoint1,LOW);
    digitalWrite(dotPoint2,HIGH);
  }
  //////////Counter Control///////////
  if (countFlag){
    if (countdown>0 && countdown<=10){
      countdown--;
      delay(1000);
      disp.write("0"+String(countdown));
    }
    else if (countdown>10){
      countdown--;
      delay(1000);
      disp.write(String(countdown));
    }
    else if (countdown==0){
      disp.write("00");
      delay(1000);
      tone(buzzer, 1000); // Send 1KHz sound signal...
      delay(1000);        // ...for 1 sec
      disp.write(" ");
      delay(1000);     
    }
  }
  else{
    disp.write(number);
  }

 }

ISR( TIMER2_COMPA_vect ){
 disp.interruptAction ();
 }

And here is the error that I get:

C:\Users\TEO\Desktop\2\2\2.ino: In function 'void loop()':

C:\Users\TEO\Desktop\2\2\2.ino:125:22: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

       disp.write("00");

                      ^

C:\Users\TEO\Desktop\2\2\2.ino:129:21: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

       disp.write(" ");

                     ^

Tone.cpp.o (symbol from plugin): In function `timer0_pin_port':

(.text+0x0): multiple definition of `__vector_7'

sketch\2.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here

collect2.exe: error: ld returned 1 exit status

exit status 1

Any thoughts on how to fix this??

Same problem in http://forum.arduino.cc/index.php?topic=512505.0; different code though.

As indicated, you have an interrupt conflict.