One-Page Checkout [Support Thread]

[njcyx]

Thanks for your efforts. It may not worth spending more time on a "retired" payment module at this time, at least opc 2.5.5 works really good on my end. I will probably keep using opc 2.5.5 with paypal express, until we decide to upgrade the payment to paypalr.

I'm not sure maybe I'm the only one who use OPC with paypal express now...

[njcyx]

I checked the log files for yesterday's issue again and it seems to be that not exactly the same as last time.

[18-Jun-2026 12:49:09 America/New_York] PHP Fatal error:  Uncaught Error: Typed property OnePageCheckout::$isVirtualOrder must not be accessed before initialization in public_html/includes/classes/OnePageCheckout.php:2572
Stack trace:
#0 /public_html/includes/classes/observers/class.checkout_one_observer.php(687): OnePageCheckout->getTaxLocations()
#1 /public_html/includes/classes/traits/NotifierManager.php(106): checkout_one_observer->update(Object(notifier), 'ZEN_GET_TAX_LOC...', Array, false, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
#2 //public_html/includes/functions/functions_taxes.php(354): base->notify('ZEN_GET_TAX_LOC...', Array, false)
#3 /public_html/includes/modules/order_total/ot_tax.php(66): zen_get_tax_locations()
#4 /public_html/includes/classes/order_total.php(96): ot_tax->process()
#5 /public_html/includes/modules/checkout_process.php(104): order_total->process()
#6 /public_html/includes/modules/pages/checkout_process/header_php.php(13): require('')
#7 /public_html/index.php(35): require('')
#8 {main}
  thrown in /public_html/includes/classes/OnePageCheckout.php on line 2572

[18-Jun-2026 12:49:09 America/New_York] Request URI: /index.php?main_page=checkout_process, IP address: xxxx
--> PHP Fatal error: Uncaught Error: Typed property OnePageCheckout::$isVirtualOrder must not be accessed before initialization in /public_html/includes/classes/OnePageCheckout.php:2572
Stack trace:
#0 /public_html/includes/classes/observers/class.checkout_one_observer.php(687): OnePageCheckout->getTaxLocations()
#1 /public_html/includes/classes/traits/NotifierManager.php(106): checkout_one_observer->update(Object(notifier), 'ZEN_GET_TAX_LOC...', Array, false, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
#2 /public_html/includes/functions/functions_taxes.php(354): base->notify('ZEN_GET_TAX_LOC...', Array, false)
#3 /public_html/includes/modules/order_total/ot_tax.php(66): zen_get_tax_locations()
#4 /public_html/includes/classes/order_total.php(96): ot_tax->process()
#5 /public_html/includes/modules/checkout_process.php(104): order_total->process()
#6 /public_html/includes/modules/pages/checkout_process/header_php.php(13): require('')
#7 /public_html/index.php(35): require('')
#8 {main}
  thrown in /public_html/includes/classes/OnePageCheckout.php on line 2572.

[18-Jun-2026 12:49:09 America/New_York] Request URI: /index.php?main_page=checkout_process, IP address: xxxx
--> PHP Fatal error: Uncaught Error: Typed property OnePageCheckout::$isVirtualOrder must not be accessed before initialization in /public_html/includes/classes/OnePageCheckout.php:2572
Stack trace:
#0 /public_html/includes/classes/observers/class.checkout_one_observer.php(687): OnePageCheckout->getTaxLocations()
#1 /public_html/includes/classes/traits/NotifierManager.php(106): checkout_one_observer->update(Object(notifier), 'ZEN_GET_TAX_LOC...', Array, false, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
#2 /public_html/includes/functions/functions_taxes.php(354): base->notify('ZEN_GET_TAX_LOC...', Array, false)
#3 public_html/includes/modules/order_total/ot_tax.php(66): zen_get_tax_locations()
#4 /public_html/includes/classes/order_total.php(96): ot_tax->process()
#5 /public_html/includes/modules/checkout_process.php(104): order_total->process()
#6 /public_html/includes/modules/pages/checkout_process/header_php.php(13): require('')
#7 /public_html/index.php(35): require('')
#8 {main}
  thrown in public_html/includes/classes/OnePageCheckout.php on line 2572. 

OnePageCheckout.php on line 2572 is the following

if ($this->isVirtualOrder === true || $this->getShippingBilling() === true) { 

[njcyx]

OPC 2.6.2. Zen cart 2.1.0

I received the following intermittent warning.

[15-Jul-2026 09:10:06 America/New_York] PHP Fatal error: Uncaught Error: Undefined constant "EMAIL_WELCOME" in /includes/modules/checkout_one_send_welcome_email.php:19
Stack trace:
#0 /includes/modules/pages/checkout_success/header_php_guest.php(43): require()
#1 /index.php(35): require('/home/...')
#2 {main}
thrown in /includes/modules/checkout_one_send_welcome_email.php on line 19

[15-Jul-2026 09:10:06 America/New_York] Request URI: /index.php?main_page=checkout_success&action=create_account, IP address: xxxx
--> PHP Fatal error: Uncaught Error: Undefined constant "EMAIL_WELCOME" in /includes/modules/checkout_one_send_welcome_email.php:19
Stack trace:
#0 /includes/modules/pages/checkout_success/header_php_guest.php(43): require()
#1 /index.php(35): require('/home/...')
#2 {main}
thrown in /includes/modules/checkout_one_send_welcome_email.php on line 19. 

Line 19 is the following
$email_text .= EMAIL_WELCOME;

[lat9]

GitHub issue created and correction committed: https://github.com/lat9/one_page_checkout/issues/474

[bumba000]

Hi All,
Running ZC 2.2.2 on PHP 8.2.31 on Clone of RC template. I believe this has happened 4 times now. Customer checking out, enters address and payment details, clicks confirm and gets the spinner. Goes on and on.. customer either reloads or clicks back and submits again. One customer ended up reloading 3 times causing 3 identical orders. The message in logs was related to email timeout php over 30 seconds. We increased the timeout to 90 seconds, but this does not prevent customers from reloading or going back and submitting again.

Thank you,
John

[bumba000]

I forgot to mention that we're now using SendGrid email service. I do not recall whether this was happening prior to using their service.

[bumba000]

Sorry to keep updating this thread. We've disabled the one page checkout, reverted back to sending mail through our own server and have again had a timeout during checkout.

[bumba000]

It's looking like this is happening due to some ModSecurity rules. Is there any recommended settings for CWP, OWASP and ModSecurity? Logs are stuffed full of legitimate traffic/users being blocked from doing regular stuff, like checkout, bookmark etc...

Thank you,
John

[lat9]

v2.6.3 of One-Page Checkout is now available for download: https://www.zen-cart.com/downloads.php?do=file&id=2095

This release contains changes associated with these GitHub issues:

#463: Correct PHP fatal error during paypalwpp special checkout, really, this time
#470: Correct "Shipping Address, Same as Billing" state management.
#474: Add missing language constants (pre-zc220) when a guest 'converts' their account after creating an order.

[dbltoe]

FYI,

Files come down as 4.6.3 vs 2.6.3