I'm using GroceryCRUD for the first time, in my controller I tried as the following :
public function user_management(){
$crud = new grocery_CRUD();
$crud->set_table('user');
$crud->set_subject('Utilisateurs');
$crud->columns('firstName','lastName','email','type');
$crud->display_as('firstName', 'Prénom');
$crud->display_as('lastName','Nom');
$crud->display_as('email','E-Mail');
$crud->display_as('type','Type');
$crud->fields('id', 'email', 'password' , 'firstName' ,'lastName', 'avatar', 'type');
$output = $crud->render();
$this->_example_output($output);
}
But I got this error message :

I searched about this issue in this forum and I found this article which didn't helped me by anything.
/topic/1130-unable-to-install-grocerycrud/
I'll appreciate any assistance :)
