I am new to wordpress plugin development. I have created a list page and an add item page. When I add successfully, I want to redirect and it is giving me this error. ![enter image description here][1] I have checked many sources but unable to find the solution so far 1. I have used `wp_redirect('admin.php?page=ccURLList'); exit;` it gives the attached error 2. I have used `no-header` in the query string of form submission, it does work but in case of any error I wanted to show the page again and that page is without any sidebar or wp stuff 3. When i move the `wp_redirect` to my main file `clickCounter.php` it says function is unknown If any of you can resolve this issue, it will be highly appreciated. **EDIT** `clickCounter.php` is my main file. It creates menus etc. I have a list page which is working. I have an add page. I have put the wp_redirect on the very first lines after <?php tag <?php // ccURLAdd.php my add page if (!defined('ABSPATH')) die('You are not allowed to call this page directly.'); wp_redirect('admin.php?page=click-counter'); exit; Below is my main file <?php // clickCounter.php my main page. /* some plugin info */ add_action('admin_menu', 'ccAdminMenu'); function ccAdminMenu() { add_menu_page("Click Counter", "Click Counter", 8, 'click-counter', "ccAdminMenuListUrls", CC_HTML_WEB . "/images/icon.png"); add_submenu_page('click-counter', 'Add New Link', 'Add Link', 8, 'click-counter-url-new', 'ccAdminAddUrl'); } function ccAdminAddUrl() { include 'ccURLAdd.php'; } [1]: https://i.sstatic.net/5t4zE.png