Android studio 2.3: Could not initialize class org.jetbrains.kotlin.android.actions.NewKotlinActivityAction

Disable the Kotlin plugin and restart Android Studio. I had the same error even after I updated the plugin. So disabling seems to be the solution for now -- unless you're using Kotlin, I guess.

The Kotlin team confirmed a fix is in the works via twitter: https://twitter.com/kotlin/status/797111726516879360

The issue is fixed in Kotlin plugin version 1.0.5-2.

Issue is fixed in new update of Kotlin, you can update your plugin from

Configuration>Plugin>Install JetBrains Plugin>Select "Kotlin" from List and hit "Update" from right menu