title: Error:Could not resolve com.android.support:appcompat-v7:26.0.0-beta1
body: <p>I have install android studio on macbook pro and I am sure I have install all the required SDK for it to work but yet still I am having issues with errors. below is the error messages</p>
  
  <blockquote>
    <p>Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.0.0-beta1.</p>
    
    <p>Could not resolve com.android.support:appcompat-v7:26.0.0-beta1.
    Required by: project :app</p>
    
    <p>No cached version of com.android.support:appcompat-v7:26.0.0-beta1 available for offline mode.</p>
  </blockquote>
  
  <p>here is my gradle</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 26
      defaultConfig {
          applicationId "com.example.air.my1st"
          minSdkVersion 15
          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(dir: 'libs', include: ['*.jar'])
      implementation 'com.android.support:appcompat-v7:26.0.0-beta1'
      implementation 'com.android.support.constraint:constraint-layout:1.0.2'
      implementation 'com.android.support:design:26.0.0-beta1'
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'com.android.support.test:runner:0.5'
      androidTestImplementation 'com.android.support.test.espresso:espresso-core:2.2.2'
  }
  </code></pre>
  
  <p>Thanks all in advance.</p>