v2.2.6: No error message when there are any input exceptions on M2.4.3

ISSUE:

We are having some issues with the checkout. When there are any input exceptions (such as postcode BT5 2QJ), the plugin seems to be showing spinner and it is not going away. I would expect it to show the input exception message at the top of the screen like on default Magento checkout. 

SOLUTION:

It seems that the code of our One Step Checkout is blocking this action. The code only shows an error message if the user enters a valid email address and then the postcode. In your case, you have not entered the email address or anything before entering the postcode, so the error did not show up. 

To resolve the issue, please edit the file: app/code/Bss/OneStepCheckout/view/frontend/web/js/model/error-processor-mixin.js as below:

Or download the file attached below to override the current file on your site.

Besides, about the spinner issue, it is not logical to stop the spinner because in this case, the user is entering a wrong postcode. As far as you know, the spinner is responsible for blocking the customer's next actions until the correct postcode is entered, so we only suggest a solution to show the error message at the top of the checkout form as expected.

If you need any further assistance, please feel free to contact us. We'd be happy to support you!