title: Android gradle sync issue
body: <p>This app was running perfectly OK without any issue. Suddenly i saw this gradle sync problems.I'm really stuck and need help. What to do now? I've uninstalled and reinstalled android support repository from SDK manager. </p>
  
  <pre><code>C:\Users\DELL\AndroidStudioProjects\Prokriti\app\build.gradle
      Error:Error:Failed to resolve: com.android.support:support-annotations:27.0.1
  Install Repository and sync project
      Error:Error:Failed to resolve: com.android.support:appcompat-v7:27.0.1
  Install Repository and sync project
      Error:Error:Failed to resolve: com.android.support:customtabs:27.0.1
  Install Repository and sync project
      Error:Error:Failed to resolve: com.android.support:cardview-v7:27.0.1
  Install Repository and sync project
      Error:Error:Failed to resolve: com.android.support:support-v4:27.0.1
  Install Repository and sync project
      Error:Error:Failed to resolve: com.android.support:support-core-utils:27.0.1
  Install Repository and sync project
  </code></pre>
  
  <p><strong>build.gradle  (app)</strong></p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 25
      buildToolsVersion "26.0.1"
      defaultConfig {
          applicationId "com.avtro.prokriti.prokriti"
          minSdkVersion 16
          targetSdkVersion 25
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
          multiDexEnabled true
  
      }
      buildTypes {
          release {
              minifyEnabled true
              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-v7:25.3.1'
      compile 'com.android.support:cardview-v7:25.3.1'
      compile 'com.android.support:design:25.3.1'
      compile 'com.android.support:support-core-utils:25.3.1'
      compile 'com.android.support:support-annotations:25.3.1'
      compile 'com.android.support.constraint:constraint-layout:1.0.2'
      compile 'com.google.android.gms:play-services-auth:11.0.4'
      compile 'com.google.firebase:firebase-core:11.0.2'
      compile 'com.google.firebase:firebase-messaging:11.0.2'
      compile 'com.google.firebase:firebase-database:11.0.2'
      compile 'com.google.firebase:firebase-auth:11.0.2'
      compile 'com.google.firebase:firebase-ads:11.0.2'
      compile 'com.afollestad.material-dialogs:core:0.9.4.5'
      compile 'com.wang.avi:library:2.1.3'
      compile 'com.google.android.gms:play-services-ads:11.0.4'
      compile 'de.hdodenhof:circleimageview:2.1.0'
      compile 'com.squareup.picasso:picasso:2.5.2'
      compile 'com.survivingwithandroid:weatherlib:1.6.0'
      compile 'com.amitshekhar.android:android-networking:1.0.0'
      compile 'com.android.support:multidex:1.0.1'
      compile 'com.squareup.okhttp:okhttp:2.0.0'
      compile 'com.facebook.android:facebook-android-sdk:[4,5)'
      compile 'com.google.firebase:firebase-storage:11.0.2'
      androidTestCompile 'junit:junit:4.12'
      compile 'javax.inject:javax.inject:1'
      compile 'com.android.support:support-v4:25.3.1'
      compile 'com.github.bumptech.glide:glide:3.8.0'
  }
  apply plugin: 'com.google.gms.google-services'
  </code></pre>
  
  <p><strong>build.gradle  (project)</strong></p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
  dependencies {
          classpath 'com.android.tools.build:gradle:2.3.3'
          classpath 'com.google.gms:google-services:3.0.0'
      }
  }
  
  allprojects {
      repositories {
          jcenter()
      }
  }
  
  task clean(type: Delete) {
      delete rootProject.buildDir
  }
  </code></pre>
  
  <p>i didnt update android studio or gradle. Android support repository is installed.</p>