I was faced with a strange problem.

I'm using android studio 3.0.1 . the latest appcompat version that grade resolve is appcompat:v7:26.0.0\_alpha1

`build.gradle (module: app)`

```
android {
    compileSdkVersion 27
    buildToolsVersion '27.0.3'
    defaultConfig {
        applicationId "someID"
        minSdkVersion 16
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 
'proguard-rules.pro'
        }
    }
    sourceSets { main { java.srcDirs = ['src/main/java', 'src/main/helpers'] } }
}

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'
    })

    // Support v7
    //compile  'com.android.support:appcompat-v7:26.+'
    compile "com.android.support:support-core-utils:27.0.2"
    compile 'com.android.support:appcompat-v7:27.0.2'
    // JSON Parsing
    compile 'com.google.code.gson:gson:2.8.2'
    compile 'com.squareup.retrofit2:converter-gson:2.1.0'
    // Retrofit
    compile 'com.squareup.retrofit2:retrofit:2.3.0'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    //testCompile 'junit:junit:4.12'
}

```

and this is `build.gradle(Project)`

```
buildscript {
    repositories {
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
    }
}

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

task clean(type: Delete) {
    delete rootProject.buildDir
}

```

i got errors like

> 
> Error:Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.android.support:support-core-utils:27.0.2.
> 
> 
> 

i'm using proxy and i can get previous releases till v:26.0.0\_alpha1

ps:i tried `compile 'com.android.support:appcompat-v7:27.+'"` and clean project