Ran into this issue on a project where some views deep into hierarchy referenced via the binding would be highlighted in red in the activity. Also import kotlinx.android.synthetic.main.controller_activity.view.* import kept getting deleted by Organize Imports Action, which Android Studio wrongly considered as unused. This nonsense was stopped by specifying the <<apply plugin: "org.jetbrains.kotlin.android.extensions">> like so (per https://plugins.gradle.org/plugin/org.jetbrains.kotlin.android.extensions)
Ran into this issue on a project where some views deep into hierarchy referenced via the binding would be highlighted in red in the activity. Also import kotlinx.android.synthetic.main.controller_activity.view.* import kept getting deleted by Organize Imports Action, which Android Studio wrongly considered as unused. This nonsense was stopped by specifying the <<apply plugin: "org.jetbrains.kotlin.android.extensions">> like so (per https://plugins.gradle.org/plugin/org.jetbrains.kotlin.android.extensions)