I am trying to try out Kotlin and the Kotlin Android extensions in Android Studio. I have tried this both in Android Studio v 1.5.1 on Ubuntu 14.04, and in Android Studio v
add apply plugin: 'kotlin-android-extensions' in app/buildgradle.
apply plugin: 'kotlin-android-extensions'
app/buildgradle
if you have already added it, try to remove it and sync gradle, when sync is complete, then add it back and Sync Gradle again. This work for me.