Error 500 validation on all payment

[wwwandreas]

Updating to the last 1.6, I receive payment and email  but at the last step of the cart I've http error 500

 

Belowe what happen after a few tests.

 

If I put in performance--> debug mode override=yes  every things works fine, no error

 

 

With performance-->debug mode  override=no

 

I’ve http error 500 with any payment (bankwire or cashondeliver)

 

http://www.xxx.it/module/bankwire/validation                                   http error 500

http://www.xxx.it/module/cashondeliveryplus/validation                 http error 500

 

In order to understand I setup debug mode true in file defines.inc.php

 

“define('_PS_MODE_DEV_', true);”

 

At the last step of the cart I’ve:

 

Fatal error: Cannot redeclare class Swift in /….tools/swift/Swift.php on line 32

 

In the prestashop log I’ve

Frontcontroller::init - Cart cannot be loaded or an order has already been placed using this cart

 

 

Really do not know what else to do.

Eny suggestion ?

 

 

many tks

[bellini13]

This error suggests that you have a custom module or override that is trying to use the older swift mailer library

Fatal error: Cannot redeclare class Swift in /….tools/swift/Swift.php on line 32