找不到gradle版本

Question

我的应用运行正常，我重启了我的电脑，试图运行它，我收到以下错误消息

Error:Could not find any version that matches com.android.tools.build:gradle:0.12.+.
Search in build.gradle 

我在Ubuntu 14.04上运行android studio 0.80

Answers in this question 建议删除sign plus可以解决问题，我将其删除但问题仍未解决

我的gradle.build文件

模块

apply plugin: 'com.android.application'

android {
    compileSdkVersion 19
    buildToolsVersion "20.0.0"

    defaultConfig {
        applicationId "com.dnsoftware.mutesmart"
        minSdkVersion 15
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    // You must install or update the Support Repository through the SDK manager to use this dependency.
    compile 'com.android.support:support-v4:21.+'

}

项目

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.12.+'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}