You do not have sufficient permissions to access this page. after wp 2.8.1

This also happened to me after the upgrade to 2.8.1. With the plugin Email-Users.

https://core.trac.wordpress.org/changeset/11595

Require all plugin page requests (?page=) to be for registered plugins pages. Provides CYA for plugins that don’t do enough cap checking. action requests not bound to a plugin page still go through.

Okay so I am not sure whats going on here but I am currently working on getting this fixed. It may take me a little while because I am unfamiliar with programming a plugin for wordpress. I currently have the plugin working but the way i did it is a bit rediculous. I found two pages that were working from the plugin:

email-users/email_users_options_form.php
and
email-users/email_users_overview.php

I then copied everything from:
email-users/email_users_group_mail_form.php
into
email-users/email_users_options_form.php

and copied everything from:
email-users/email_users_send_group_mail.php
into
email-users/email_users_overview.php

In order to get email-users/email_users_group_mail_form.php to open up email-users/email_users_send_group_mail.php when i submit the query I edited the line in email-users/email_users_group_mail_form.php

<form name=”SendEmail” action=”post-new.php?page=email-users/email_users_send_group_mail.php” method=”post”>

and changed it to:

<form name=”SendEmail” action=”post-new.php?page=email-users/email_users_overview.php” method=”post”>

So now whenever I want to write an email to all my users i have to go to:
/wp-admin/admin.php?page=email-users/email_users_options_form.php

Yes i know this is completely screwed up, but I use this plugin on a daily basis and this is going to have to work for now. I am going to try to edit the plugin and see if I can figure out how to make it work properly.

Found the solution, do the followings:

0. deactivate adsense-delux
1. download adsense-delux from servier
2. open up adsense-delux.php and change admin_head to admin_menu
3. upload back to server.
4. check – you should have permission now.

reference:

http://www.thefilipinoentrepreneur.com/2009/07/20/adsense-deluxe-plugin-for-wordpress-2-8-1.htm

Good luck 😉

I have a very similar problem with the WP-PHPList plugin. Any idea where to fix it?

<?php
/*
Author: David Young
Author URI: http://www.funkypenguin.co.za
Description: Administrative options for WP-PHPList

This file is the configuration options for the WP-PHPList plugin
(http://www.funkypenguin.co.za/wp-phplist)

It should be placed within your wp-content/plugins/wp-phplist directory
*/

load_plugin_textdomain('wpcf'); // NLS
$location = get_option('siteurl') . '/wp-admin/admin.php?page=wp-phplist/wp-phplist-options.php'; // Form Action URI

/*Lets add some default options if they don't exist*/

if(get_option('wp_phplist_slug') == '') {
	add_option('wp_phplist_slug', 'wp-phplist.php');
}

if(get_option('wp_phplist_spage') == '') {
	add_option('wp_phplist_spage', '1');
}
if(get_option('wp_phplist_title') == '') {
	add_option('wp_phplist_title', 'Our Newsletters');
}
if(get_option('wp_phplist_phplist_path') == '') {
	add_option('wp_phplist_phplist_path', 'lists');
}
/*check form submission and update options*/
if ('process' == $_POST['stage'])
{
update_option('wp_phplist_slug', $_POST['wp_phplist_slug']);
update_option('wp_phplist_spage', $_POST['wp_phplist_spage']);
update_option('wp_phplist_title', $_POST['wp_phplist_title']);
update_option('wp_phplist_phplist_path', $_POST['wp_phplist_phplist_path']);
}

/*Get options for form fields*/
$wp_phplist_slug = get_option('wp_phplist_slug');
$wp_phplist_spage = get_option('wp_phplist_spage');
$wp_phplist_title = get_option('wp_phplist_title');
$wp_phplist_phplist_path = get_option('wp_phplist_phplist_path');
?>

<div class="wrap">
  <h2><?php _e('WP-PHPList Options', 'wpcf') ?></h2>
  <form name="form1" method="post" action="<?php echo $location ?>&updated=true">
	<input type="hidden" name="stage" value="process" />
    <table width="100%" cellspacing="2" cellpadding="5" class="form-table">
      <tr valign="top">
        <th scope="row"><?php _e('PHPList public pages slug:') ?></th>
        <td><input id="inputid" name="wp_phplist_slug" type="text" id="wp_phplist_slug" value="<?php echo $wp_phplist_slug; ?>" size="50" />
        <br />
<?php _e('The "slug" to the main PHPList page, relative to wordpress. Defaults to the name of the script. You may want to create a custom rewrite rule.', 'wpcf') ?></td>
      </tr>
      <tr valign="top">
        <th scope="row"><?php _e('PHPList default subscribe page:') ?></th>
        <td><input id="inputid" name="wp_phplist_spage" type="text" id="wp_phplist_spage" value="<?php echo $wp_phplist_spage; ?>" size="50" />
        <br />
<?php _e('Enter the number of the default subscribe page to use, or leave blank to let PHPList generate an index', 'wpcf') ?></td>
      </tr>
      <tr valign="top">
        <th scope="row"><?php _e('PHPList embedded page title:') ?></th>
        <td><input id="inputid" name="wp_phplist_title" type="text" id="wp_phplist_title" value="<?php echo $wp_phplist_title; ?>" size="50" />
        <br />
<?php _e('Enter the title to be displayed on the page with the embedded PHPList results', 'wpcf') ?></td>
      </tr>
      </tr>
      <tr valign="top">
        <th scope="row"><?php _e('PHPList relative path:') ?></th>
        <td><input id="inputid" name="wp_phplist_phplist_path" type="text" id="wp_phplist_phplist_path" value="<?php echo $wp_phplist_phplist_path; ?>" size="50" />
        <br />
<?php _e('Enter the path of your PHPList installation, relative to WordPress', 'wpcf') ?></td>
      </tr>
     </table> 

    <p class="submit">
      <input type="submit" name="Submit" value="<?php _e('Update Options', 'wpcf') ?> &raquo;" />
    </p>
  </form>
</div>

http://www.thefilipinoentrepreneur.com/2009/07/20/adsense-deluxe-plugin-for-wordpress-2-8-1.htm

has instructions

It seems to have worked just fine for me – hand editing v0.8 of adsense-deluxe.php and wordpress 2.8.2 will now let me back in to the settings page.