i can't use mpr121 sensor with interrupt help please!!

hello everybody . i am trying to do an musical instrunment with capacitive buttons. my project is working with pushbuttons perfectly but i couldn’t do that with mpr 121 module. mpr121 module is working fine alone, also my own code works fine alone but if i try put them together i can’t get anything. after that i realized mpr121 doesnt work with interrupt.i put most basic code for show you my problem you maybe thought the problem is about to serial but it is not. i tried to blink led but it did not also work.

#include <TimerOne.h>
#include <Wire.h>
#include "Adafruit_MPR121.h"
Adafruit_MPR121 cap = Adafruit_MPR121();

uint16_t currtouched = cap.touched();// if i remove this line interrupt works fine. the problem start on this line

void setup() 
  Timer1.initialize(100000); // set a timer of length 100000 microseconds (or 0.1 sec - or 10Hz => the led will blink 5 times, 5 cycles of on-and-off, per second)
  Timer1.attachInterrupt( timerIsr ); // attach the service routine here
void loop()
Serial.println("i am loop and  im working");

void timerIsr()
Serial.println("i am interrupt  and im workinf");

You must call cap.begin() before you call any other method of this object. You shouldn't call object methods in the variable definitions as the code get reordered by the IDE. Put such stuff in either setup() or loop() (or any routine called from there).

And calling any Serial method inside interrupt context is a very bad idea. You may see errors that seem completely unrelated but are caused by such "must-not-do"s.