Android : cannot resolve symbol 'android' on android studio

I have been making an app showing MapView, It got build and I even am using it on my device now that i want to add still more functionality , but suddenly studio is giving errors "cannot resolve symbol 'android'."...!!!!

I updated studio to 0.8.6 (latest) .... but damn..!! nothing changes ..

Errors :

import com.google.android.maps.GeoPoint
import com.google.android.maps.MapView
import com.google.android.maps.OverlayItem
import com.google.android.maps.ItemisedOverlay

Please help .. Thanks in advance