Fatal error on PHP 8+ “Unsupported operand types: int + string”

Following up on the previous fatal error I reported (which you fixed — thank you).

I’m now getting a new fatal error, but only on combined orders (orders created via your plugin’s combination feature). Regular orders are unaffected.

Uncaught TypeError: Cannot access offset of type string on string in
/wp-content/plugins/e-transactions-wc/templates/admin/order/payment-info.php:44

The failing code is:

php

foreach ( $transactions as $transaction ):
    if(empty($transaction_number)){
        $transaction_number = $transaction['captured'] ? $transaction['numtrans'] : $transaction['auth_numtrans'];
    }

$transactions comes from an order meta field maintained by the e-transactions-wc payment plugin — normally an array of associative arrays, each describing one payment transaction (captured, numtrans, auth_numtrans, amount, card_type, etc.). On combined orders, at least one entry in this array ends up being a plain string instead of an associative array, which causes the fatal TypeError on PHP 8+.

This strongly suggests that when combining orders, the plugin doesn’t preserve the internal structure of this payment gateway meta — it’s likely copied/merged as if it were a simple value, instead of being handled as a structured array coming from another plugin.

Could you check how order meta belonging to other plugins (not just WooCommerce core order data) is copied when combining orders — specifically whether serialized/array meta values are preserved correctly, rather than being flattened or concatenated as strings?

Environment:

• WordPress + WooCommerce (Cloudways hosting)
• PHP version: 8.3
• Plugin version: 2.0.7
• Payment gateway: e-transactions-wc

Thanks!