title: error: incompatible types: NonExistentClass cannot be converted to Annotation @error.NonExistentClass()
body: <p>I am trying to generate Doka docs of my project. While generating I am getting an error like above. I have searched so many but could not able to get solution to this. I have gone through <a href="https://stackoverflow.com/questions/45099688/error-error-nonexistentclass-kotlin-in-multi-module-dagger-project">this</a> link also. Here it is saying it might be a dagger related issue. I have tried these all solution also but not worked for me. I am posting here my all Gradle files for more clarification. if any one faced this issue or know the way to solve Please do comments.</p>
  
  <p><strong>Project Gradle :</strong> </p>
  
  <pre><code> buildscript {
          ext.kotlin_version = '1.3.20'
          ext.dokkaVersion = '0.9.17'
          repositories {
              google()
              jcenter()
          }
          dependencies {
              classpath 'com.android.tools.build:gradle:3.3.1'
              classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
              classpath "org.jetbrains.dokka:dokka-android-gradle-plugin:$dokkaVersion"
              classpath "org.jetbrains.kotlin:kotlin-allopen:1.3.20"
  
              // NOTE: Do not place your application dependencies here; they belong
              // in the individual module build.gradle files
          }
      }
  
      allprojects {
          repositories {
              google()
              jcenter()
          }
      }
  
      task clean(type: Delete) {
          delete rootProject.buildDir
      }
  </code></pre>
  
  <p><strong>App Gradle :</strong> </p>
  
  <pre><code>    apply plugin: 'com.android.application'
  
  apply plugin: 'kotlin-android'
  
  apply plugin: 'kotlin-android-extensions'
  
  apply plugin: 'kotlin-kapt'
  apply plugin: 'org.jetbrains.dokka-android'
  
  android {
      compileSdkVersion 28
      defaultConfig {
          applicationId "com.xx.xxx.xxx"
          minSdkVersion 23
          multiDexEnabled true
          targetSdkVersion 28
          versionCode 1
          versionName "1.0.3"
          multiDexEnabled true
          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
      }
      dokka {
          outputFormat = 'html'
          outputDirectory = "$buildDir/documentation"
      }
  
      dataBinding {
          enabled = true
      }
  
      signingConfigs {
          platform {
              storeFile file("../certs/platform.keystore")
              storePassword 'xxxxxxxx'
              keyAlias 'platform'
              keyPassword 'xxxxxxxx'
          }
      }
  
      buildTypes {
          release {
              signingConfig signingConfigs.platform
              zipAlignEnabled true
          }
          debug {
              debuggable true
              signingConfig signingConfigs.platform
              zipAlignEnabled true
              testCoverageEnabled = true
          }
      }
  
      androidExtensions {
          experimental = true
      }
  
  }
  
  dependencies {
      implementation fileTree(include: ['*.jar'], dir: 'libs')
      implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
      implementation 'androidx.appcompat:appcompat:1.0.0-alpha1'
      implementation 'androidx.legacy:legacy-support-v4:1.0.0-alpha1'
      implementation 'com.android.support:support-v4:28.0.0'
      implementation 'com.android.support:appcompat-v7:28.0.0'
      testImplementation 'junit:junit:4.12'
      implementation 'com.android.support:multidex:1.0.3'
      implementation 'com.android.support:recyclerview-v7:28.0.0'
      implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
      implementation project(':library')
      implementation 'com.android.support:design:28.0.0'
      implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
      annotationProcessor 'com.google.dagger:dagger-compiler:2.21'
      annotationProcessor 'com.google.dagger:dagger-android-processor:2.21'
      implementation 'com.google.dagger:dagger:2.21'
      implementation 'com.google.dagger:dagger-android:2.21'
      implementation 'com.google.dagger:dagger-android-support:2.21'
      kapt 'com.google.dagger:dagger-compiler:2.21'
      kapt 'com.google.dagger:dagger-android-processor:2.21'
      androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1-alpha3'
      androidTestImplementation 'com.android.support.test:runner:1.0.1'
      implementation 'com.android.support.test:rules:1.0.2'
      implementation 'com.google.code.findbugs:jsr305:2.0.1'
  </code></pre>
  
  <p><strong>library gradle :</strong></p>
  
  <pre><code>    apply plugin: 'com.android.library'
  apply plugin: 'kotlin-android'
  apply plugin: 'kotlin-android-extensions'
  apply plugin: 'kotlin-kapt'
  apply plugin: "kotlin-allopen"
  apply from: '../buildsystem/android_commons.gradle'
  
  allOpen {
      annotation 'com.xx.xxxx.xxxx.xxxxx'
  }
  android {
  
      defaultConfig {
          versionName "1.0"
          buildConfigField "String", "xx", "\"xx\""
      }
  
      androidExtensions {
          experimental = true
      }
  
  }
  
  dependencies {
      implementation fileTree(include: ['*.jar'], dir: 'libs')
      implementation 'androidx.appcompat:appcompat:1.0.0-alpha1'
      testImplementation 'junit:junit:4.12'
      testImplementation 'org.mockito:mockito-core:1.10.19'
      androidTestImplementation 'androidx.test:runner:1.1.0-alpha3'
      androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha3'
      implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
      implementation 'com.google.dagger:dagger:2.21'
      implementation 'com.google.dagger:dagger-android:2.21'
      implementation 'com.google.dagger:dagger-android-support:2.21'
      kapt 'com.google.dagger:dagger-compiler:2.21'
      kapt 'com.google.dagger:dagger-android-processor:2.21'
      annotationProcessor 'com.google.dagger:dagger-compiler:2.21'
      annotationProcessor 'com.google.dagger:dagger-android-processor:2.21'
      implementation 'com.google.guava:guava:23.3-android'
  
  }
  
  repositories {
      mavenCentral()
  }
  </code></pre>
  
  <blockquote>
    <p><strong>Error</strong>:- Task :library:kaptReleaseKotlin FAILED error: incompatible types: NonExistentClass cannot be converted to Annotation
    @error.NonExistentClass()</p>
  </blockquote>