I install fresh installation of wordpress in my server sub-folder call blog.

So in the beginning I access the site mydomain/blog and it works perfectly.

But when I changed the permalinks settings to Post name option in the settings, all urls giving me 403 - forbidden error including frot-end.

And then I realize it is because of .htaccess file inside the /blog folder as bellow.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

# END WordPress

It was automatically create after I change the permalinks settings. When I rename the .htaccess file to another name homepage is accessible and not others.

Does anybody have an idea to what should I do in order to get the things back in action.

Thanks in advance.