compileSdkVersion
buildToolsVersion
support:appcompat-v7
support:recyclerview-v7
support:support-core-utils
support:support-fragment
support:support-v4

上面这些版本的大版本号都应该一一对应，升级其中一个，其他也都相应升级。如下面两个图：

参考：failed to resolve com.android.support:appcompat-v7:22 and com.android.support:recyclerview-v7:21.1.2