You do not have sufficient permissions to access this page.

Sounds like your user permissions somehow got changed. Do you have a backup of your database from when things were working?

Adding this since it came up via a search for teh solution. if I hit it, someone else will as well.

https://markjaquith.wordpress.com/2006/03/28/wordpress-error-you-do-not-have-sufficient-permissions-to-access-this-page/

This worked great for me. In case the link goes dead, let me reproduce it here. Upload this as force-upgrade.php and run it from a web browser:

`
<?php
/*
WordPress Force Upgrade Script
Copyright (C) 2006 Mark Jaquith

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

function txfx_log($text) {
echo $text . ”;
}

switch ($_GET[‘step’]) :
case “1”:
require(‘wp-config.php’);
txfx_log(‘WordPress loaded…’);
require(‘wp-admin/upgrade-functions.php’);
txfx_log(‘Upgrade functions loaded…’);
wp_cache_flush();
txfx_log(‘Object cache flushed…’);
make_db_current();
txfx_log(‘Database made current…’);
upgrade_160();
txfx_log(‘Data upgraded…’);
$wp_rewrite->flush_rules();
txfx_log(‘Rewrite rules flushed…’);
wp_cache_flush();
txfx_log(‘Object cache flushed…’);
txfx_log(”);
txfx_log(‘Hopefully that did it! DELETE THIS FILE FROM YOUR SERVER NOW!‘);
txfx_log(‘And then, try to access your /wp-admin/

');
        break;
    default :
        txfx_log('This script will attempt to upgrade your database.  It is intended for users of WordPress 1.5 or later.');
        txfx_log('<strong>You should delete this script from your server after you are done using it!</strong>');
        txfx_log('');
        txfx_log('<a href="?step=1">Click here</a> to attempt the upgrade');
        break;
endswitch;
?>

Thanks drmiketemp

follow this post really work