Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at com.majaxtn.fullprogress.Playing.showQuestion(Playing.java:81)
at com.majaxtn.fullprogress.Playing.onResume(Playing.java:132)
81:txtQuestionNum.setText(String.format("%d / %d",thisQuestion, totalQuestion));
132: showQuestion(index);
How To Fix?
=>
Check *  :

* = (TextView) findViewById(R.id.txtScore);* = (TextView) findViewById(R.id.txtTotalQuestion);