Android: R.java: error <identifier> expected

It sounds like you have accidentally defined a menu item in your XML with an id of =action_setting.

For example:

<menu>
    <item 
        android:id="@+id/=action_settings" />
</menu>

Remove the = from your menu XML and you should be good to go.

I had the same problem, because I defined a string without name in my resources. like:

<string name="">some text</string>

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