anybody can help please
 

When I modify navbar template and save it, showing this message..

Forbidden
You don't have permission to access /admincp/template.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

please help me how to make that can be permission to write it...

Hi, what are OS are you using, Windows or Linux? Dedicated server or Hosting? please answer this questions for help.

I Use OS Linux and Hosting, so what should I do?

This may be due to mod_security.

While mod_security can be a very powerful tool, misconfigured or overly strict rule sets can interfere with vBulletins Operation. Below for Apache users you can use an htaccess file and add a specific rule to disable mod_security.

Make or edit your forum .htaccess file and add the following code

Code:
<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

Note, place this file in your main forum directory.

See this also thread: http://www.vbulletin.com/forum/showthread.php?t=167121

It's Work, Thx Marco van Herwaarden