I am having this issue in Android studio.
Error:(22, 13) Failed to resolve: com.android.support:appcompat-v7:26.0.0 Install
you forgot to add add alpha1 in module area
compile 'com.android.support:appcompat-v7:26.0.0-alpha1'
use maven repository in project area that's it
allprojects { repositories { jcenter() maven { url "https://maven.google.com" } } }