工具栏菜单项无法在Android 4.4（19）上单击

I have a Android app for Android sdk version 23. Now I try to make it available for user using versions 19 to 23. All is working fine expect the toolbar in the head of the app. I can't click an menu item. Nothing happend when I click. Also if I insert Log.v() there is no message in the debug view.I have a Android app for Android sdk version 23