Could not create directory. /home/XXXXXXXX/public_html/wp-content/plugins/really-simple-ssl/
Plugin installation failed.

Permissionlarla ilgili bir problem olabilir mi?

EDIT:

.htaccess dosyasında aşağıdaki kod bloğunu kaldırdım sorun halloldu.

# BEGIN WP CERBER GROOVE
# Protection of admin scripts is enabled (CVE-2018-6389)
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI} ^(.*)wp-admin/+load-scripts.php$ [OR,NC]
RewriteCond %{REQUEST_URI} ^(.*)wp-admin/+load-styles.php$ [NC]
RewriteCond %{HTTP_COOKIE} !cerber_groove_x_96Iq3crLvSmFA5UXhjN2lYdMOE0tBQW=GV9dcuYRh7NQElOCJH2eZWFXfa5kSMo
RewriteRule (.*) - [R=403,L]
</IfModule>
# END WP CERBER GROOVE