Fatal error: Cannot use object of type stdClass as array in C:\xampp\htdocs\ov400\application\views\Useraccount\Userlist.php on line 38

You are using result() function to fetch records, but this give records as object not as array. If you want to get array than you will have to use result_array().

function userList() {   
   $data['userlist'] = $this->Useraccount_mod->getUser_list();
   $this->load->view('Useraccount/Userlist', $data);
}

Method 1:

function getUser_list() {
  $query = $this->db->query("select * from users")->result_array(); //here we can use result() as well but it gives object not array
  return $query;
}


<tbody>
  <?php
  if ($userlist > 0) {
      foreach ($userlist as $row) {
          ?>
          <tr>                                        
              <td width="100"><?php echo $row['username']; ?></td> 
              <td width="100"><?php echo $row['name']; ?></td> 
              <td width="100"><?php echo $row['address']; ?></td> 
              <td width="100"><?php echo $row['creatdate']; ?></td> 
              <td width="100"><?php echo $row['updateddate']; ?></td> 
          </tr>
          <?php
      }
  } else {
      ?>
      <tr>
          <td colspan="3" align="center"><strong>No Record Found</strong></td>
      </tr>
      <?php
  }
  ?>
</tbody>

Method 2:

function getUser_list() {
  $query = $this->db->query("select * from users")->result(); 
  return $query;
}


<tbody>
  <?php
  if ($userlist > 0) {
      foreach ($userlist as $row) {
          ?>
          <tr>                                        
              <td width="100"><?php echo $row->username; ?></td> 
              <td width="100"><?php echo $row->name; ?></td> 
              <td width="100"><?php echo $row->address; ?></td> 
              <td width="100"><?php echo $row->creatdate; ?></td> 
              <td width="100"><?php echo $row->updateddate; ?></td> 
          </tr>
          <?php
      }
  } else {
      ?>
      <tr>
          <td colspan="3" align="center"><strong>No Record Found</strong></td>
      </tr>
      <?php
  }
  ?>
</tbody>