会遇到下面的报错信息：
exception 'yii\base\InvalidRouteException' with message 'Unable to resolve the request "site/error".' in /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/base/Module.php:461
Stack trace:
#0 /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/web/ErrorHandler.php(80): yii\base\Module->runAction('site/error')
#1 /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/base/ErrorHandler.php(95): yii\web\ErrorHandler->renderException(Object(yii\web\NotFoundHttpException))
#2 [internal function]: yii\base\ErrorHandler->handleException(Object(yii\web\NotFoundHttpException))
#3 {main}
Previous exception:
exception 'yii\base\InvalidRouteException' with message 'Unable to resolve the request "site/index".' in /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/base/Module.php:461
Stack trace:
#0 /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/web/Application.php(83): yii\base\Module->runAction('site/index', Array)
#1 /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/base/Application.php(375): yii\web\Application->handleRequest(Object(yii\web\Request))
#2 /Users/yuzhiyuan/Documents/htdocs/yii-application/mobile/web/index.php(18): yii\base\Application->run()
#3 {main}
Next exception 'yii\web\NotFoundHttpException' with message 'Page not found.' in /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/web/Application.php:95
Stack trace:
#0 /Users/yuzhiyuan/Documents/htdocs/yii-application/vendor/yiisoft/yii2/base/Application.php(375): yii\web\Application->handleRequest(Object(yii\web\Request))
#1 /Users/yuzhiyuan/Documents/htdocs/yii-application/mobile/web/index.php(18): yii\base\Application->run()
#2 {main}
解决办法：
找到common\config\bootstrap.php
找到上面的文件，添加一个新的别名：
Yii::setAlias('应用名', dirname(dirname(__DIR__)) . '/目录名’);
比如：Yii::setAlias('mobile', dirname(dirname(__DIR__)) . '/mobile’);
这样就正常显示了，我去，让我调整了一个下午，坑爹啊
