Attempt to invoke virtual method 'void android.media.AudioManager.setRingerMode(int)' on a null object reference

[Mohamed_Tamer]

Hi @sadirul_islam786 please read this first:

How to ask a question?

Asking questions To improve the chance of getting help on the forum please follow these recommendations when posting a question: Do your homework first Search for similar questions/answers on the forum. Try forum search and also Google your problem. Try to solve the problem yourself, and describe what you have tried. It is much more rewarding to help someone who has tried himself first. Post in the right categorie, post only once and do not steal topics Make sure that you post your question …

And provide some more info like showing your blocks and a screenshot of the error