Solution For An Error : Resolve this dependency for ':app@debug/compileClasspath': Could not resolve com.android.support.appcompact. Your computer must be connected to internet to resolve this problem. Android Studio > File > Settings > Build, Execution, Deployment Gradle Uncheck the offline work and click OK to exit from Settings window Go to Build Menu > Rebuild project Click the Try again link in Gradle notification and your pc will download the required library files from the internet and your problem will be resolved.