why can't I use my android studio 2.3 Instant run features?

Question

My AS is 2.3 official version

and I already open the Instan run on the settings

but it can't use,and the lightning symbol is always not light,just like this

I don't why this is,who has other ideas?

Answer 1

Make sure the Android Gradle plugin is version 2.3.0 and Gradle is version 3.3.

Else it wont work. Android studio should tell you that by default. Normally when you open your project or after a clean build.