检索项目的父项时出错 – Android Studio

下载新L SDK和20 SDK后，尝试刷新，构建或清理我的项目，我得到一个

Error:Error retrieving parent for item: No resource found that matches the given name '@android:TextAppearance.Material.SearchResult.Subtitle'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.ActionBar.Title'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.ActionBar.Menu'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.PopupMenu.Small'.
Error:Error retrieving parent for item: No resource found that matches the given name '@android:TextAppearance.Material.SearchResult.Title'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.ActionMode.Title'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.PopupMenu.Large'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.PopupMenu.Large'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.ActionBar.Subtitle'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.ActionMode.Subtitle'.
Error:Error retrieving parent for item: No resource found that matches the given name 'android:TextAppearance.Material.Widget.PopupMenu.Small'.

这是我的build.gradle

apply plugin: 'com.android.application'
buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.12.+'
    }
}

repositories {
    maven { url 'https://oss.sonatype.org/content/repositories/snapshots' }
}


    signingConfigs{
        release {
           ... Stuff Here ...
        }
    }
    buildTypes {
        debug {
            runProguard true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
            zipAlign true
            debuggable true
        }
        release {
            runProguard true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
            zipAlign true
            signingConfig signingConfigs.release

        }
    }

    dexOptions {
        incremental true
    }
}

android {
    compileSdkVersion 'android-L'
    buildToolsVersion '20.0.0'

    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 'L'
    }
}


dependencies {
    compile fileTree(dir: 'libs', include: '*.jar')
    ...
    Some Projects
    ...
    compile 'com.android.support:cardview-v7:+'
    compile 'com.android.support:recyclerview-v7:+'
    compile 'com.android.support:appcompat-v7:+'
}

我觉得ive尝试了一切，我不知道还有什么要尝试。
任何帮助将不胜感激。

我刚从0.6.0 Canary升级到新的Android Studio Beta(0.8.0)

结果，我不得不把目标和编译版本到L，这意味着我不能在旧的SDK上运行我的应用程序。如果你想要你的应用程序运行在SDK 19和更低的你必须设置你的编译和目标版本为19和你的最小的SDK到任何你需要的版本。

接下来，您必须将导入调整为与您选择编译的SDK兼容的版本。例如，如果你想在sdk 19上使用v7支持库，你必须像这样导入它：compile compile’c​​om.android.support:appcompat-v7:20。 ”