警告 mkdir()：权限被拒绝

Question

我在 WordPress 站点中使用插件。 以下代码的第一行发出警告：mkdir(): Permission denied:

$cnssUploadDir = wp_upload_dir();
$cnssBaseDir = $cnssUploadDir['basedir'].'/';
$cnssBaseURL = $cnssUploadDir['baseurl'].'';
$cnssPluginsURI = plugins_url('/', __FILE__);

All directories are set to 755.
I would appreciate some pointers on how to fix this issue.

Sorry, I should have posted the full details from Query Monitor:
`Warning    mkdir(): Permission denied  1`
    `wp-includes/functions.php:2060    mkdir()`
    `wp-includes/functions.php:2060    wp_mkdir_p()`
    `wp-includes/functions.php:2371    wp_upload_dir()`
    `wp-content/plugins/easy-social-icons/easy-social-icons.php:14`