Square for Woocommerce Transaction Errors

Hi @agould45,

(Status code NOT_FOUND: Card on file not found)
(Status code CARD_TOKEN_USED: Card nonce already used with a different idempotency key; please request new nonce.)

For the Card Nonce errors, it is usually the same as the Card not found items. Card Nonce errors are almost always caused by theme issues, where the theme interferes with the data being passed to Square. This is seen where themes override the Cart/Checkout pages, usually with the Checkout Form area. Plugins can also do this, but most commonly it’s improperly coded themes.

The best way to troubleshoot this is to do a conflict test to see what might be blocking it. You can read more about plugin and theme conflicts here:
?https://docs.woocommerce.com/document/woocommerce-self-service-guide/
The best way to determine if the issue is being caused by a theme and/or plugin is to do the following:

1. Temporarily switch your theme to the Storefront or Twenty Twenty Theme.
2. Disable all plugins except for WooCommerce and Square (and your shipping gateway if there is one).
3. Test to see if the issue has been resolved.

If that resolves the issue, then one-by-one you can switch back your theme and re-enable your plugins, testing in between, until you find the one causing the conflict.

We do *highly* recommend a staging site for these tests so that your Live site is unaffected. A staging site is a clone or copy of the Live site, used for testing. You can reach out to your Host if you need to have a staging site set up, as they usually can assist you with this.

Please try this and let us know the results!

We haven’t heard back from you in a while, so I’m going to mark this as resolved – if you have any further questions, you can start a new thread.

We can’t do it on a staging site because there is no way of testing whether it works. The errors occur for ~4% of transactions.

They don’t happen when we use our own cards to pay. Therefore, we need to try it on the actual site where actual customers are paying. Otherwise, we won’t know for sure if what we’re doing worked.

Before I go and do it on our live site, does it make sense to you still that the theme and/or a plugin would only be causing the error on ~4% of transactions? Why wouldn’t it be happening for all transactions if the issue is the theme?

Hi @agould45

Before I go and do it on our live site, does it make sense to you still that the theme and/or a plugin would only be causing the error on ~4% of transactions? Why wouldn’t it be happening for all transactions if the issue is the theme?

Yes, it is still possible that this is coming from a theme/plugin. I am not saying this is the exact scenario that is happening to you but is possible that it could be a similar issue. There may be resource exceptions like the server is running out of RAM or CPU every X hours due to heavy customer demand, which could create failures in some payments being processed during a peak time, but not at other times. During those peak resource utilization, maybe the nonces aren’t being generated correctly due to lack of resources causing some payments to fail.

Does that help you understand this error might be possible due to a theme/plugin?

Please try the conflict test and let us know the results!

So I did the conflict test. The theme was NOT causing the issue. I was and still am using the Ocean theme. There was a conflict between square and a plugin I was using.

The conflict was between square and cartflows. Cartflows was saving each customer’s payment method before the transaction went through. This was causing the card_nonce and card_not_found errors.

I disabled cartflows and the error hasn’t happened since

Awesome!

That’s great to know you found the conflict and fixed it. Thanks for keeping us posted.