问题一：
Config error.
Disk [admin] not configured, please add a disk config in `config/filesystems.php`.此问题是因为config\admin.php的upload项的disk默认设置为admin，config/filesystem.php中disk没有admin项导致的报错
'upload' => [// Disk in `config/filesystem.php`.'disk' => 'admin',// Image and file upload path under the disk above.'directory' => ['image' => 'images','file' => 'files',],
],只要把disk的值改成public即可
'upload' => [// Disk in `config/filesystem.php`.'disk' => 'public',// Image and file upload path under the disk above.'directory' => ['image' => 'images','file' => 'files',],
],如果后台是存放图片路径不同，也可以自己在config/filesystem.php的disk数组中新增一个admin