问题解决方法
执行命令php artisan cache:clear并赋予/storage文件夹读写权限：chmod -R 777 storage；
若在执行php artisan cache:clear时出现错误：Uncaught UnexpectedValueException: The stream or file "/storage/logs/laravel.log" could not be opened: failed to open stream: Permission denied in /vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php:87，需要赋予/storage/log读写权限：chmod -R 777 storage/logs；
此时再执行php artisan cache:clear，若继续出错：[ErrorException] file_put_contents(/bootstrap/cache/services.php): failed to open stream: Permission denied，需要赋予bootstrap/cache读写权限：chmod -R 777 bootstrap/cache；
再执行php artisan cache:clear，若仍然出错：[PDOException] SQLSTATE[HY000] [1045] Access denied for user 'xxx'@'127.0.0.1' (using password: YES)，则需要查看 laravel 的数据库配置是否正确。
来源：/zhangzhijian/p/10789524.html
