You need to use a Theme.AppCompat theme (or descendant) with this activity. Change to Theme.AppCompat causes other error

Question

I use appcompat v22.1.0 in my App and use Toolbar. Everything was fine when I use Theme.AppCompat.Light.NoActionBar. When I start implement AlertDialog

Answer 1

Fixed my problem by using MainActivity.this (or YourActivityName.this)

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);

Make sure you already Theme.AppCompat and extending AppCompatActivity.