title: Failed to resolve: core Affected Modules: app
body: <p>I'm using Android Studio 3.5.3 and my Gradle version is 5.4.1 .
  After adding <strong>butterknife</strong> my project don't sync and it shows an error that is "Failed to resolve: core".</p>
  
  <p>i added</p>
  
  <pre><code>compileOptions {
          sourceCompatibility JavaVersion.VERSION_1_8
          targetCompatibility JavaVersion.VERSION_1_8
      }
  </code></pre>
  
  <p>in android tag in madule:app.</p>
  
  <p>and also added butterknife dependencies:</p>
  
  <pre><code>implementation 'com.jakewharton:butterknife:10.2.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.1'
  } 
  </code></pre>
  
  <p>as like as butterknife steps in <a href="https://github.com/JakeWharton/butterknife" rel="nofollow noreferrer">https://github.com/JakeWharton/butterknife</a></p>
  
  <p>my build.gradle(module:app)</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'com.jakewharton.butterknife'
  
  
  android {
      compileSdkVersion 29
      buildToolsVersion "29.0.2"
      defaultConfig {
          applicationId "com.example.myapplication"
          minSdkVersion 15
          targetSdkVersion 29
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
          multiDexEnabled true
  
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
          }
      }
      compileOptions {
          sourceCompatibility JavaVersion.VERSION_1_8
          targetCompatibility JavaVersion.VERSION_1_8
      }
  }
  
  dependencies {
      implementation fileTree(dir: 'libs', include: ['*.jar'])
      implementation 'androidx.appcompat:appcompat:1.1.0'
      implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
      implementation  'androidx.legacy:legacy-support-v4:1.0.0'
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'androidx.test:runner:1.2.0'
      androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
      implementation 'com.android.support:multidex:1.0.3'
      implementation 'com.jakewharton:butterknife:10.2.1'
      annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.1'
  
  
  }
  repositories {
      mavenCentral()
  }
  </code></pre>
  
  <p>my build.gradle(project:My Application)</p>
  
  <pre><code>// Top-level build file where you can add configuration options common to all sub-projects/modules.
  
  buildscript {
      repositories {
          google()
          mavenCentral()      
          jcenter()
  
  
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:3.5.3'
          classpath 'com.jakewharton:butterknife-gradle-plugin:10.2.1'
  
          // NOTE: Do not place your application dependencies here; they belong
          // in the individual module build.gradle files
      }
  }
  
  allprojects {
      repositories {
          jcenter()
          mavenCentral()
          google()
         maven { url "https://jitpack.io" }
          maven { url "https://maven.google.com"}
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>And This is my error code</p>
  
  <pre><code>ERROR: Failed to resolve: core
  Affected Modules: app
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/mufzs.png" rel="nofollow noreferrer">my error code</a></p>