I had the same problem this morning after updating to .6.0. You need to change you gradle version in /projectName/build.gradle
classpath 'com.android.tools.build:gradle:0.11.+'
Open your SDK manager and download the new version of the build tools 19.1 then change the following line in /projectName/moduleName/build.gradle
android {
compileSdkVersion 19
buildToolsVersion "19.1" //This version needs to be updated to 19.1 after SDK update
...
}
Then sync your gradle files and you should be good to go!