Forbidden You don’t have permission to access / on this server.

You don’t have permission to access / on this server.

The main reason for the error when you logging in to the site “admin” page to make edits, many times mod_security alerts are triggered. Mod_security will prevent you from making edits and you will get the error code that is configured within mod_security. The error code such as 599 is mod_security is related to this.

To resolve the issue you need to add the following code in the root directory of the .htaccess file.
SecFilterEngine Off
SecFilterScanPOST Off
SecRule REMOTE_ADDR “^111\.111\.11\.111$” phase:1,nolog,allow,ctl:ruleEngine=Off

Here “^111\.111\.11\.111$” is ip address of your desktop.