403 – Forbidden: Access is denied. You do not have permission to view this direc

403 forbidden means that your browser isn’t able to load the scripts up because your server isn’t allowing it. This is a hard one to solve. Because anything could be blocking the server.
– Most likely this is a server permissions/ownership issue, so ask your host what’s going on
– check your .htaccess files for anything strange.
– try a full Manual Upgrade, to make sure all the WordPress files are there and correct..
– Make sure to backup everything (including database) before doing any action, in case.

thanks for replay
i’ve called my service host provider and told me no problem found on our server..
but when i searched about this problem i found someone talking about htaccess file, i seen my files on cpanel, file htaccess not there,
so i created htacces file with myself and uploaded it, the same errors found..
there is my htaccess file code:
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

is that correct ?
thanks