One-Page Checkout [Support Thread]

opc 2.7.0. zc 2.1.0. php 8.2

I just received the following warning file. Not sure if it is related to OPC or not. First time to receive this warning.

[07-Oct-2026 18:51:35 America/New_York] ERROR: Failed sending email to: "Guest Customer, **do not remove**" <> with subject: "example.com - New Password" (failed validation)

njcyx:

opc 2.7.0. zc 2.1.0. php 8.2

I just received the following warning file. Not sure if it is related to OPC or not. First time to receive this warning.

[07-Oct-2026 18:51:35 America/New_York] ERROR: Failed sending email to: "Guest Customer, **do not remove**" <> with subject: "example.com - New Password" (failed validation)

That's not the full log; from which page (admin vs. storefront) was the log issued?

Yeah, I don't know why the log is not completed. But that is all the info I have. I will report if it happens again.

I believed it is from the storefront, not the admin page.

Oh, it's probably coming from PHPMailer ... not that that helps.

lat9:

Oh, it's probably coming from PHPMailer ... not that that helps.

Actually, it's coming from the zen_mail function in /includes/functions/functions_email.php (for zc210). Find line 115 of that file

error_log(sprintf(EMAIL_SEND_FAILED . ' (failed validation)', $to_name, $to_email_address, $email_subject));

and change that to

trigger_error(sprintf(EMAIL_SEND_FAILED . ' (failed validation)', $to_name, $to_email_address, $email_subject));

that'll create a "real" log record, showing where the email originated.

Thank you as always. I will give it a shot.

If you don't mind, can you please help me to delete my domain name in post #3081 and #3082? I forgot to delete it when I submit the post. Sorry for the inconvenience.

njcyx:

Thank you as always. I will give it a shot.

If you don't mind, can you please help me to delete my domain name in post #3081 and #3082? I forgot to delete it when I submit the post. Sorry for the inconvenience.

Done

Thank you so much. I have updated functions_email.php per your instruction and I will let you know if we receive any new log files.

We received lots of DDoS attack recently. I'm not sure if it is related.

I think i found a bug in OPC.

Seems to only be happening with international orders (state province not saving) (screen shot 1 is an example of input information)

When I put in international address and click save it does not show the correct state or province. (see screen shot 2)

This is causing us to get the wrong address when shipping orders.

This is happening on all my sites that using OPC. I am not sure what is causing this. Nothing in the error log.

I also noticed that if I put the billing address as international and put a ship to to a US destination if put the International province in the Ship to.

chadlly2003:

I think i found a bug in OPC.

Seems to only be happening with international orders (state province not saving) (screen shot 1 is an example of input information)

When I put in international address and click save it does not show the correct state or province. (see screen shot 2)

This is causing us to get the wrong address when shipping orders.

This is happening on all my sites that using OPC. I am not sure what is causing this. Nothing in the error log.

I also noticed that if I put the billing address as international and put a ship to to a US destination if put the International province in the Ship to.

Forgot to mentioned version i am using is 2.7.0

chadlly2003:

I think i found a bug in OPC.

Seems to only be happening with international orders (state province not saving) (screen shot 1 is an example of input information)

When I put in international address and click save it does not show the correct state or province. (see screen shot 2)

This is causing us to get the wrong address when shipping orders.

This is happening on all my sites that using OPC. I am not sure what is causing this. Nothing in the error log.

I also noticed that if I put the billing address as international and put a ship to to a US destination if put the International province in the Ship to.

It seems when you pick an international destination the 'State/Province' is the issue. It saves correctly but when you save it shows the address without the 'State/Province' displaying

Sorry for all the post. Just to be clear....

When a customer selects or updates an international billing or shipping address, the state/province does not always display correctly.

For example, I tested the following addresses:

Billing Address – Netherlands

City: Vlijmen

Province: North Brabant

Country: Netherlands

Shipping Address – United States

• City: Miami
• State: Florida
• Country: United States

During checkout, I noticed two problems:

1. The Netherlands address does not display North Brabant, even though the province was entered.
2. In another test, North Brabant appeared in the US shipping address instead of Florida.

This seems to happen when updating or switching either the billing or shipping address in OPC.

I checked the completed order in phpMyAdmin and the Zen Cart admin. Both showed the correct billing and shipping states, which suggests the problem may be related to how addresses are formatted or refreshed during checkout rather than how they're saved.

One-Page Checkout (OPC) Bug – Billing and Shipping Address Fields Getting Mixed Up

After testing on localhost, I was finally able to reproduce the issue.

Steps to reproduce: (during testing this would happen randomly)

1. Go to One-Page Checkout with different billing and shipping addresses.
2. Click Edit on the billing address.
3. While the billing editor is open, click Edit on the shipping address so both address forms are open simultaneously.
4. Make changes to either address.
5. Click Save Changes on one of the forms.

Actual result:

Address information can become mixed between the two forms.

For example, I tested:

Billing: United States — Wellington, Florida

Shipping: Netherlands — Vlijmen, North Brabant

After saving, the Netherlands shipping address displayed the city as Miami instead of Vlijmen, while the street address, postal code, and country remained from the Netherlands address.

Expected result:

Each address editor should operate independently. Saving the billing address should not modify the shipping address, and vice versa.

Alternatively, OPC could prevent both address editors from being open simultaneously.

Additional findings:

I checked the completed order information in phpMyAdmin and the Zen Cart admin during earlier tests, and the stored billing and shipping states were correct.

I also investigated the address_format table, but that turned out to be a separate issue involving how certain countries display provinces. I restored those changes and reproduced this problem again with the original configuration.

This appears to be related to how OPC handles the two address forms when both are open, possibly involving JavaScript field selectors or AJAX processing.

Has anyone encountered this behavior, and could the OPC address-editing JavaScript be allowing values from the two forms to interfere with each other?

At first, I thought it might be https://github.com/zencart/zencart/issues/7900

However, OPC uses a different variable for the address blocks.

OPC issues #297 and #380 are in 2.7.0, but they seem to cover only the company and address-line-2.

I would open an issue in GitHub. I'm sure lat9 can come up with a fix with your instructions for recreating the problem.

Sometimes the forum doesn't notify us of a new post.

dbltoe:

At first, I thought it might be https://github.com/zencart/zencart/issues/7900

However, OPC uses a different variable for the address blocks.

OPC issues #297 and #380 are in 2.7.0, but they seem to cover only the company and address-line-2.

I would open an issue in GitHub. I'm sure lat9 can come up with a fix with your instructions for recreating the problem.

Sometimes the forum doesn't notify us of a new post.

just to be sure i downloaded a new copy of zencart and installed opc. Same result. The screen shot you will see for shipping state province is supposed to be North Brabant but when you save it it does not show in the address filed. Happens both on shipping and billing address..

chadlly2003:

dbltoe:

At first, I thought it might be https://github.com/zencart/zencart/issues/7900

However, OPC uses a different variable for the address blocks.

OPC issues #297 and #380 are in 2.7.0, but they seem to cover only the company and address-line-2.

I would open an issue in GitHub. I'm sure lat9 can come up with a fix with your instructions for recreating the problem.

Sometimes the forum doesn't notify us of a new post.

just to be sure i downloaded a new copy of zencart and installed opc. Same result. The screen shot you will see for shipping state province is supposed to be North Brabant but when you save it it does not show in the address filed. Happens both on shipping and billing address..

That behavior has nothing to do with OPC. The address_format used for the Netherlands (at least in zc22x) is 5, which indicates that an address layout displays without the state/province.

$firstname $lastname$cr$streets$cr$postcode $city$cr$country

chadlly2003:

One-Page Checkout (OPC) Bug – Billing and Shipping Address Fields Getting Mixed Up

After testing on localhost, I was finally able to reproduce the issue.

Steps to reproduce: (during testing this would happen randomly)

1. Go to One-Page Checkout with different billing and shipping addresses.
2. Click Edit on the billing address.
3. While the billing editor is open, click Edit on the shipping address so both address forms are open simultaneously.
4. Make changes to either address.
5. Click Save Changes on one of the forms.

Actual result:

Address information can become mixed between the two forms.

For example, I tested:

Billing: United States — Wellington, Florida

Shipping: Netherlands — Vlijmen, North Brabant

After saving, the Netherlands shipping address displayed the city as Miami instead of Vlijmen, while the street address, postal code, and country remained from the Netherlands address.

Expected result:

Each address editor should operate independently. Saving the billing address should not modify the shipping address, and vice versa.

Alternatively, OPC could prevent both address editors from being open simultaneously.

Additional findings:

I checked the completed order information in phpMyAdmin and the Zen Cart admin during earlier tests, and the stored billing and shipping states were correct.

I also investigated the address_format table, but that turned out to be a separate issue involving how certain countries display provinces. I restored those changes and reproduced this problem again with the original configuration.

This appears to be related to how OPC handles the two address forms when both are open, possibly involving JavaScript field selectors or AJAX processing.

Has anyone encountered this behavior, and could the OPC address-editing JavaScript be allowing values from the two forms to interfere with each other?

Tracking issue created on GitHub: https://github.com/lat9/one_page_checkout/issues/503

Yes, this is a common address format in Europe where you don't use the state as the information is already in the postal code.

If you want it anyway, you can use format 12.

pilou2:

Yes, this is a common address format in Europe where you don't use the state as the information is already in the postal code.

If you want it anyway, you can use format 12.

I made the changes that lat9 suggested but for some reason I am getting the same results. Am I misunderstanding something here?

Also for example if someone picks the netherlands then the State/Province is required. But your saying its in the postal code. Can you explain. (not sure what format 12 is)

chadlly2003:

pilou2:

Yes, this is a common address format in Europe where you don't use the state as the information is already in the postal code.

If you want it anyway, you can use format 12.

I made the changes that lat9 suggested but for some reason I am getting the same results. Am I misunderstanding something here?

Also for example if someone picks the netherlands then the State/Province is required. But your saying its in the postal code. Can you explain. (not sure what format 12 is)

In Admin->Locations->Countries, edit Netherland and change address format from 5 to 12. It should add the state field in the address. These format are defined in the database table address_format. There are predefined setting that you can change or add a new one and set any country to use it.

After this change, if you still don't see the state in the address, there might be an issue with OPC.

About the postal code, there are some numbers or letters representing the state. For exemple in France, the first 2 numbers in the postal code design the state like 75 for Paris (Ile de France), 69 for Rhone. Writing both just double the information which is why the state is not required in a standard address.