Failed to resolve: com.android

Question

I am facing an issue in Android Studio 3.0. I am using Windows 7 - 64bits.

Whenever I wanted to launch my app on my phone, it crashes. So when I googled it, I found out that there may be version mismatch and so I applied some changes to my build.gradle file. After the changes and a little debugging, I was not able to solve this error.

Error: Failed to resolve: com.android

The following is my MyProject/app/build.gradle file:

apply plugin: 'com.android.application'

allprojects {
    repositories {
        jcenter()
        google()
    }
}

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.2"
    defaultConfig {
        applicationId "com.planner.reemshams.projectplannerpro"
        minSdkVersion 17
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
})
    compile 'com.android.support:appcompat-v7-26+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.android.support:recyclerview-v7-24+'
    compile 'com.android.support:cardview-v7-26+'
    testCompile 'junit:junit:4.12'
    implementation 'com.android.support:design-v7-26+'
}

Edit: I got the following at the Messages tab when I tried building/running the app.

Error:Could not resolve all files for configuration ':app:debugCompileClasspath'.
> Could not find com.android.support:appcompat-v7-26+:.
  Searched in the following locations:
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.jar
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.pom
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.jar
      https://jcenter.bintray.com/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.pom
      https://jcenter.bintray.com/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.jar
      https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.pom
      https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7-26+//appcompat-v7-26+-.jar
  Required by:
      project :app
> Could not find com.android.support:recyclerview-v7-24+:.
  Searched in the following locations:
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.jar
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.pom
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.jar
      https://jcenter.bintray.com/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.pom
      https://jcenter.bintray.com/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.jar
      https://dl.google.com/dl/android/maven2/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.pom
      https://dl.google.com/dl/android/maven2/com/android/support/recyclerview-v7-24+//recyclerview-v7-24+-.jar
  Required by:
      project :app
> Could not find com.android.support:cardview-v7-26+:.
  Searched in the following locations:
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.jar
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.pom
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/cardview-v7-26+//cardview-v7-26+-.jar
      https://jcenter.bintray.com/com/android/support/cardview-v7-26+//cardview-v7-26+-.pom
      https://jcenter.bintray.com/com/android/support/cardview-v7-26+//cardview-v7-26+-.jar
      https://dl.google.com/dl/android/maven2/com/android/support/cardview-v7-26+//cardview-v7-26+-.pom
      https://dl.google.com/dl/android/maven2/com/android/support/cardview-v7-26+//cardview-v7-26+-.jar
  Required by:
      project :app
> Could not find com.android.support:design-v7-26+:.
  Searched in the following locations:
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/design-v7-26+//design-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/m2repository/com/android/support/design-v7-26+//design-v7-26+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/design-v7-26+//design-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/google/m2repository/com/android/support/design-v7-26+//design-v7-26+-.jar
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/design-v7-26+//design-v7-26+-.pom
      file:/C:/Users/WinDows7/AppData/Local/Android/sdk/extras/android/m2repository/com/android/support/design-v7-26+//design-v7-26+-.jar
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/design-v7-26+//design-v7-26+-.pom
      file:/C:/Program Files/Android/Android Studio/gradle/m2repository/com/android/support/design-v7-26+//design-v7-26+-.jar
      https://jcenter.bintray.com/com/android/support/design-v7-26+//design-v7-26+-.pom
      https://jcenter.bintray.com/com/android/support/design-v7-26+//design-v7-26+-.jar
      https://dl.google.com/dl/android/maven2/com/android/support/design-v7-26+//design-v7-26+-.pom
      https://dl.google.com/dl/android/maven2/com/android/support/design-v7-26+//design-v7-26+-.jar
  Required by:
      project :app

Answer 1

Your code should have never worked. The dependencies are incorrect.

implementation 'com.android.support:appcompat-v7-26.+'
implementation "com.android.support:recyclerview-v7-26.+"
implementation "com.android.support:design-26.+"

Should be

implementation 'com.android.support:appcompat-v7:26.+'
implementation "com.android.support:recyclerview-v7:26.+"
implementation "com.android.support:design:26.+"

Answer 2

You should not work with librairies that end with 26+ or 24+. You should specify your version. Try this code , it works normally (I have tested it)

apply plugin: 'com.android.application'


allprojects {
    repositories {
        jcenter()
        google()
    }
}

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.2"
    defaultConfig {
        applicationId "com.planner.reemshams.projectplannerpro"
        minSdkVersion 17
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    implementation 'com.android.support:recyclerview-v7:26.1.0'
    implementation 'com.android.support:cardview-v7:26.1.0'
}

Answer 3

As mentioned in latest gradle release version you should avoid using dynamic dependencies, so replace your dependencies with newest version number:

    compile 'com.android.support:appcompat-v7-26+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.android.support:recyclerview-v7-24+'
    compile 'com.android.support:cardview-v7-26+'
    implementation 'com.android.support:design-v7-26+'

Then you can follow this thread , here I have solved this error with steps mentioned. Even after, If it doesn't get resolved, paste your logcat from terminal window. I will happy to help here.

Thanks.