Android Studio 2.1 Cannot resolve symbol 'R'

Question

Android Studio 2.1, Java V8 Update 91, Gradle 2.1.0 .

I know that this questions has been asked many times here, but none of the recommendation solutions works out.

Answer 1

Maybe the error may cause for the tools, trying install Android SDK Build Tools from Tools > Android > SDK Manager. or maybe this error can be caused by adding an activity to a namespace that is different to the root, you can trying >>Import com.example.MyApplication.R; or your also can clean o rebuild your project in Build > Clean Project or Build > Rebuild Project