Administrator role has all capabilities turned on. So turn on all checkboxes and you will get the default Administrator role.
If you has some other custom roles and changed them, try to deactivate/activate plugins to which these roles belongs.
If it will not help, you may a chance to restore roles manually with SQL tool. URE makes roles backup before you fire the 1st changes to the site roles. You may find this backup record at wp_options DB database table with this select command:
SELECT * FROM wp_options where option_name like '%backup_user_roles%' or option_name like '%user_roles%'
So your task is to put option_value field content from backup record to the live one with the ‘wp_user_roles’ key. Change ‘wp’ to the prefix of your database if you changed it.
This post could help
https://shinephp.com/how-to-change-wordpress-user-role-capabilities/
