No need to remove the admin folder - it contains some useful utilities to check configuration and to clear out stuck emails

When I add admin folder back it shows like this

Warning: Admin directory should be removed.

I'd set $g_admin_checks = OFF; in the config. This reduces a DB query on the logon / index page. Removing the admin folder doesn't really increase security and removes the admin check pages - you could remove install.php

In terms of the cookie thing - have you set any configuration options regarding to cookies?

Does your path to the website include a / or not in the conifg?

@grangeway

Removing the admin folder doesn't really increase security

I disagree. Leaving access to the admin folder open is most definitely a security risk (leaking system information such as DB version, system paths, etc and even allowing anyone to execute the install script) because these pages don't check if user is permitted access

IMO $g_admin_checks = OFF is meant for development purposes and should not be used on production systems.

Muhammed, with regards to the cookie message, could be due to a case sensitivity issue in the cookie or use of invalid characters in the cookie prefix. Please search on this tracker for related issues.

Since it this is not a MantisBT issue but a request for help in configuring the system, I'll resolve this as no change required.

It was the issue with varnish. I have added the varnish exception for mantis url's in the varnish configuration file and now mantis working fine. Thanks to all....

Thanks for providing feedback.