java.lang.RuntimeException: Unable to instantiate application

说明：

安卓开发编译时候运行一起正常，但是打包或者拷贝编译过的包安装，app打不开，报错：

java.lang.RuntimeException: Unable to instantiate application

原因：

根目录下的build.gradle的classpath为最新的2.3.3会报这个错

// Top-level build file where you can add configuration options common to all sub-projects/modules.buildscript {    repositories {        jcenter()    }    dependencies {        classpath 'com.android.tools.build:gradle:2.3.3'        // NOTE: Do not place your application dependencies here; they belong        // in the individual module build.gradle files    }}allprojects {    repositories {        jcenter()    }}task clean(type: Delete) {    delete rootProject.buildDir}

节约：

classpath版本改小一点：改成2.2.3。

如果：改成2.1.3则会运行编译不通过，会报错：

所以最终代码：

// Top-level build file where you can add configuration options common to all sub-projects/modules.buildscript {    repositories {        jcenter()    }    dependencies {        classpath 'com.android.tools.build:gradle:2.2.3'        // NOTE: Do not place your application dependencies here; they belong        // in the individual module build.gradle files    }}allprojects {    repositories {        jcenter()    }}task clean(type: Delete) {    delete rootProject.buildDir}

总结：这样，你所打的包，发布给别人就能装上了。应该是gragle打包的问题，以后sdk应该就会自动修复了。