You do not have sufficient permissions to access this page while making a plugin

Try

function crudindex(){
   add_options_page('Crud Dashboard', 'Crudboard', 'manage_options', 'crud', 'crudboard');
   add_options_page(NULL, 'Crudboard', 'manage_options', 'create_crud', 'crudboard');
}

and your anchor tag like

<a class="add_new-h2" href="https://wordpress.stackexchange.com/questions/137953/<?php bloginfo("url');?>/wp-admin/options-general.php?page=create_crud">Add New</a>

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)