安装完运行报错 哪位大神帮忙看一下 谢谢

Parse error: syntax error, unexpected 'class' (T_CLASS), expecting identifier (T_STRING) or variable (T_VARIABLE) or '{' or '$' in E:\server\www\blog\bootstrap\app.php on line 42

$app->singleton(
Illuminate\Contracts\Debug\ExceptionHandler::class, //这行报错
App\Exceptions\Handler::class
);