I have created a k2 item for a new menu on my site. and then select menu type k2-> item and then in the next options it`s ask me to chose a k2 item from light box.
And in the popup box it is showing an error message.

Not Acceptable

An appropriate representation of the requested resource /namskarbollywood/administrator/index.php could not be found on this server.

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

for more info please check below link screen shot:

i.imgur.com/hgg13g9.png

Regards,
Amit
www.focusobject.com

Which version of K2 and Joomla! are you using?

K2 is a Joomla! extension package developed by JoomlaWorks, released under the GNU/GPL v2 license.

Copyright © 2006 - 2014 JoomlaWorks Ltd. All rights reserved.

(Last update: December 8th, 2014 - Version 2.6.9)

Regards,
Amit

Are you using any other K2 plugins or extensions?

This issue was resolved several versions ago but it is possible that a K2 plugin is causing this conflict.

I don`t know about this that i am using other k2 plugins or extensions. If you need i can provide you my administrator link and their user name and password by email.

Regards,
Amit

You can look Extensions -> Plugin Manager and look for K2 plugins or you can look directly at Extensions -> Extension Manager -> Manage to look for k2 related components.

I have searched all k2 extension in "Extension Manager: Manage ".

Check attach file.

Please check screen shot URL: i.imgur.com/t5ST1sN.jpg

Regards,
Amit

Make sure that Joseta is updated to its latest version.

What do you mean about "Joseta"?

Regards,
Amit

Is your site multilingual?