将原先完好的网站移植到群晖nas上之后运行报错，请问怎么解决？

An uncaught Exception was encountered

Type: Error

Message: Call to a member function real_escape_string() on boolean

Filename: /volume1/web/www/perfectfont/diy/system/database/drivers/mysqli/mysqli_driver.php

Line Number: 391

Backtrace:

File: /volume1/web/www/perfectfont/diy/poscms/model/Member.php
Line: 341
Function: where

File: /volume1/web/www/perfectfont/diy/dayrui/controllers/admin/Login.php
Line: 36
Function: admin_login

File: /volume1/web/www/perfectfont/diy/Init.php
Line: 99
Function: require

File: /volume1/web/www/perfectfont/index.php
Line: 49
Function: require

File: /volume1/web/www/perfectfont/admin.php
Line: 8
Function: require