This Activity already has an action bar supplied by the window decor (FEATURE_ACTION_BAR)

Question

This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_ACTION_BAR and set windowActionBar to false in your theme to use a Toolba

Answer 1

In your AppTheme style use,

Theme.AppCompat.Light.NoActionBar

instead of

Theme.AppCompat.Light.DarkActionBar

You are setting a theme that has an actionbar and then you are setting toolbar as an actionbar. That's why your are getting this error.

Use the theme that has no actionbar instead and it will fix the issue.