Currently I am part of a wordpress.org site. Something has happened in that the old administrator login details allow us to login, but every user only has "editor" capacities, and no account has permissions to edit appearance, users etc. We now need help locating which account holds administrator status so that we can try to login restore users.
If the users are there but something has happened to the administrator status of one, I would use phpMyAdmin.
First, backup the database. Open the database in phpMyAdmin
Note that where I use
wp_ your installation may be different. It might be something like
wptd_. It should be obvious when looking at the table list.
Jump into the
wp_users table and find the ID number of the user you would like to be the admin. That's all you need there.
Now go to the
wp_usermeta table and run the following SQL statement substituting the actual ID number for the number 1 in this example.
SELECT * FROM `wp_usermeta` WHERE `user_id` = 1 AND `meta_key` = "wp_capabilities"
You should end up with a single result with this in the meta_value column
Change it to
That user will now be an administrator. If they already were, then there are other problems somewhere.
If none of that makes any sense, you shouldn't be messing with phpMyAdmin.
I am going to assume from your question that you have no idea as to how to view functions.php or access the database.
So the best idea is to contact original developer of the website. Or if you can no longer contact them, then try the hosting company where the site is currently hosted and ask them to update your account in the database as per other answer (you may have to prove that you are authorised to do this).
And if that doesn't work, and you do have access to the Control Panel access or the database, then hire someone to do this for you.