«explode(): Passing null to parameter #2 ($string) of type string is deprecated in vendor/mage2pro/core/Framework/Form/Element/Multiselect.php on line 40»

A part of https://github.com/mage2pro/core/issues/173

[
    Mage2.PRO: {
        "mage2pro/core": "10.3.8",
        "Magento": "2.4-develop",
        "PHP": "8.1.11",
        "URL": "https://localhost.com:2190/admin/admin/system_config/edit/section/df_payment/",
        "Time": "2023-08-30 18:47:08",
        "Referer": "https://localhost.com:2190/admin/admin/system_config/",
        "IP Address": "158.181.235.66",
        "Request Method": "GET",
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36"
    }
    channel: main
    context: []
    datetime: Monolog\DateTimeImmutable "2023-08-30T18:47:08.255185+00:00"
    extra: []
    level: 400
    level_name: ERROR
    message: Deprecated Functionality: explode(): Passing null to parameter #2 ($string) of type string is deprecated in C:\work\clients\m\latest\code\vendor\mage2pro\core\Framework\Form\Element\Multiselect.php on line 40
]

1   Df\Framework\Log\Dispatcher::handle
    https://github.com/mage2pro/core/tree/10.3.8/Framework/Log/Dispatcher.php#L86

2   Monolog\Logger::addRecord
    vendor/monolog/monolog/src/Monolog/Logger.php:399

3   Monolog\Logger::error
    vendor/monolog/monolog/src/Monolog/Logger.php:650

4   Magento\Framework\Logger\LoggerProxy::error
    lib/internal/Magento/Framework/Logger/LoggerProxy.php:130

5   Magento\Framework\App\Bootstrap::run
    lib/internal/Magento/Framework/App/Bootstrap.php:269

mage2pro / core

«explode(): Passing null to parameter #2 ($string) of type string is deprecated in vendor/mage2pro/core/Framework/Form/Element/Multiselect.php on line 40» #336