Quando tento compilar meu aplicativo, recebo o seguinte erro

Error:Execution failed for task ':app:dexDebug'.
> com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.7.0_60\bin\java.exe'' finished with non-zero exit value 2

Se eu me livrar do Facebook SDK para Android, ele será compilado sem problemas.

Meu build.gradle:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 21 //tried 19 and 22 changing targetSdkVersion and buildToolsVersion accordingly
    buildToolsVersion "21.1.2"

    defaultConfig {
        applicationId "..."
        minSdkVersion 15
        targetSdkVersion 21
    }

    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-project.txt'
        }
    }

...

}

dependencies {
    ...
    compile 'com.facebook.android:facebook-android-sdk:3.23.1' //tried older versions as well
}