java - Can I call a Async task inside a runnable postdelayed?

I have done a counter, who handler a limit time for my loading. Its something like: If the process spend 10s, and my loading minimum time is 15s, this counter will execute a postdelayed with 5s.

But something is wrong, cause my app is crashing.

Here is what Ive done so far, in resume:

 new MyHandler(secondsLeft, new LoadingFinishedCallBack() {
            @Override
            public void timeFinished() { 
               //CALLING A ASYNC TASK HERE
      }).execute();

class MyHandler {
public void execute(){
       runnable = new Runnable() {
        @Override
        public void run() {
            handler.removeCallbacks(runnable);
            callback.onTimeLeftFinished();
        }
    };

    handler.postDelayed(runnable,timeLeft);
   }
}

But for some reason, my app is crashing when doInBackground is calling, inside the async task. I dont know why, cuz the error log doesnt show anything.

Can you guys help me pls