If you encountered this error that is super frustrating, breaks your site and throws 404 and 403 errors that don’t provide you with enough information, here are a few checks you might want to perform in order to fix it:

1

Verify that your Apache server has the option AllowOveride set to All

2

Check that the option mod_rewrite is activated

3

Review your server’s error log file looking for the following:

[rewrite:error] (…)[rewrite:error] (…) FollowSymLinks and SymLinksIfOwnerMatch are both off, so the RewriteRule directive is also forbidden (…)  and SymLinksIfOwnerMatch are both off, so the RewriteRule directive is also forbidden (…)

If that’s the case you will have to activate FollowSymLinks and SymLinksIfOwnerMatch in your .htaccess file by adding the following at the beginning:

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