String to Array conversion bei onTransactionCreate event

Notice: Array to string conversion :: \QUI\ERP\Order\EventHandling::onTransactionCreate

#0 /var/www/projects/q_erp/packages/quiqqer/quiqqer/lib/QUI/Events/Manager.php(304): QUI\Events\Event->fireEvent('onTransactionCr...', Array, false)
#1 /var/www/projects/q_erp/packages/quiqqer/payment-transactions/src/QUI/ERP/Accounting/Payments/Transactions/Factory.php(89): QUI\Events\Manager->fireEvent('transactionCrea...', Array)
#2 /var/www/projects/q_erp/packages/quiqqer/payments/src/QUI/ERP/Accounting/Payments/Gateway/Gateway.php(215): QUI\ERP\Accounting\Payments\Transactions\Factory::createPaymentTransaction(16.07, Object(QUI\ERP\Currency\Currency), '56165044-23b5-1...', '41ae5b43f2ed7a9...', Array)
#3 /var/www/projects/q_erp/packages/quiqqer/payment-paypal/src/QUI/ERP/Payments/PayPal/Payment.php(475): QUI\ERP\Accounting\Payments\Gateway\Gateway->purchase(16.07, Object(QUI\ERP\Currency\Currency), Object(QUI\ERP\Order\OrderInProcess), Object(QUI\ERP\Payments\PayPal\PaymentExpress))
#4 /var/www/projects/q_erp/packages/quiqqer/payment-paypal/ajax/executeOrder.php(35): QUI\ERP\Payments\PayPal\Payment->capturePayPalOrder(Object(QUI\ERP\Order\OrderInProcess))
#5 [internal function]: {closure}('56165044-23b5-1...', 'PAY-8FL68197MW7...', 'Y37QP2D444CZN', '1')
#6 /var/www/projects/q_erp/packages/quiqqer/quiqqer/lib/QUI/Ajax.php(342): call_user_func_array(Object(Closure), Array)
#7 /var/www/projects/q_erp/packages/quiqqer/quiqqer/lib/QUI/Ajax.php(205): QUI\Ajax->callRequestFunction('package_quiqqer...')
#8 /var/www/projects/q_erp/packages/quiqqer/quiqqer/lib/ajax.php(94): QUI\Ajax->call()
#9 /var/www/projects/q_erp/packages/quiqqer/quiqqer/ajax.php(16): require('/var/www/projec...')
#10 /var/www/projects/q_erp/ajax.php(26): require('/var/www/projec...')
#11 {main}
{
    "request": "http:\/\/erp.peat.pcsg\/ajax.php",
    "errorFilename": false,
    "userId": 772250033,
    "username": "peat"
}