Hi,
First, that Mollie plugin was not developed by us but by SkySpider, so we can't change its code. That said, the error message says quite a lot.
"Unable to connect to Mollie. Maximum number of retries (5) reached." comes from Mollie's own PHP library, in mollie-api/src/HttpAdapter/CurlMollieHttpAdapter.php. It is raised only when curl cannot establish the connection at all: DNS resolution failure, connection refused, TLS handshake failure, empty reply, or a connection taking more than 2 seconds. It is never an API key problem, a wrong key would come back as a 401 with a different message. So your server is failing to reach api.mollie.com.
Two things worth checking:
1. Plain connectivity. Over SSH if you have access to it on your server:
curl -v https://api.mollie.com/v2/methods
2. The certificate. That library ignores your server's certificate store and forces its own cacert.pem bundled inside the plugin folder. api.mollie.com is now served from Google Cloud with a Google Trust Services certificate, so a cacert.pem that is a few years old might fail the check on every attempt and produces exactly your error. The deprecation notices in your log confirm the bundled library is old: those implicit nullable parameters were fixed in mollie-api-php 2.76.0, so the copy in your plugin is 2.75.0 or older.
To see the real curl error instead of the generic retry message, put this in a file at the root of your website and load it in your browser:
<?php
$ca = glob(__DIR__.'/plugins/hikashoppayment/mollie/mollie-api/vendor/composer/ca-bundle/res/cacert.pem');
$ch = curl_init('https://api.mollie.com/v2/methods');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
if($ca) curl_setopt($ch, CURLOPT_CAINFO, $ca[0]);
curl_exec($ch);
echo ($ca ? 'certificate file: '.$ca[0] : 'no bundled certificate file found').'<br/>';
echo 'curl error '.curl_errno($ch).' : '.curl_error($ch);Delete the file once you have the answer.
If it prints error 60 or 77, it is the certificate file, and updating the plugin, or replacing that cacert.pem with a current one, should fix it. If it prints error 7 or 28, the connection itself is blocked and your host has to open it. If it prints error 0, the connection works and the problem is elsewhere in the plugin.
In any case, the deprecation notices show that the plugin is not ready for PHP 8.4, so it would be worth asking SkySpider for an updated version.
You can contact him on kamron AT skyspider DOT com DOT au
HIKASHOP ESSENTIAL 60€The basic version. With the main features for a little shop.
HIKAMARKETAdd-on Create a multivendor platform. Enable many vendors on your website.
HIKASERIALAdd-on Sale e-tickets, vouchers, gift certificates, serial numbers and more!
MARKETPLACEPlugins, modules and other kinds of integrations for HikaShop
