Did you try under WordPress default user with ‘administrator’ role (ID=1)?
User Role Editor hides ‘administrator’ role and all users with this role from any user (ID != 1) who can edit and/or promote other users. It’s possible to switch off this rule via custom filter though.
Oh ok, so for the custom filter can you tell me how to do that?
Basically, I want my other administrators to be able to add administrators.
Try this filter:
// Switch off URE's protection of users with 'administrator' role from each other and other users with 'edit_users' capability
add_filter( 'ure_supress_administrators_protection', 'switch_off_ure_admin_protection', 10, 1);
function switch_off_ure_admin_protection( $switch_off ) {
$switch_off = true;
return $switch_off;
}