After several times moving WordPress websites from one host to another, I get this painfully permission denied for superadmin user “You do not have sufficient permissions to access this page”. The frontend page was all fine. But I can’t access the admin page. Then I found these people who have the same problem and found the solution (http://wordpress.org/support/topic/sudden-you-do-not-have-sufficient-permissions-to-access-this-page-error).
The main cause is the database prefix changes. It cause the wordpress doesn’t recognize the admininstrator privilege. if you look into the wp_options table, the option_name from roles is wp_user_roles. The wp_ should match the table prefix. So if you change the wp_options table to en_options, then you must change the options_name to en_user_roles. That’s how the wordpress recognize the roles.
Besides that, user to role mapping also use the table prefix. You can see it in wp_usermeta tables. There is a meta_key called wp_capabilities. The wp_ is the table prefix of the wordpress tables. So if you change the table prefix e.q. wp_usermeta to en_usermeta, then you should change the wp_capabilities to en_capabilities.
Thats how you fix the permission problem to wp_admin page.
Have a good day