laravel 出现unserialize(): Error at offset 0 of 40 bytes解决办法

You have to set a news Key Generate because

php artisan key:generate

After that test again to run the Laravel Application

php artisan serve

 原因是你本来的项目是并没有.env文件或者你是刚添加的.env文件，系统需要重新生成一个key。