<I'm using Android Studio. When I add button in ac...

# stackoverflow

[user]

I'm using Android Studio. When I add button in activity_main The app stop on the AVD
When I add button in "activity_main" The app stop on the AVD
but If I delete the button, app run normally.
If I make the button as comment or delete this, The app run correctly.
What should I do?
please teach me What I have to do.
This is my "activity_main" file