diff --git a/CHANGELOG.md b/CHANGELOG.md
index 826c55f9..1e75a76c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## WIP
 
+* RATESWX-306: installment: prevent fatal error message in checkout on unreachable gateway
+
 ## Version 7.0.1 - Released on 2024-06-07
 
 RATESWSX-303: fix admin-session logout endless redirect & make admin-session urls more unified
diff --git a/src/Components/InstallmentCalculator/DependencyInjection/subscriber.xml b/src/Components/InstallmentCalculator/DependencyInjection/subscriber.xml
index 927f6c1f..c966af9e 100644
--- a/src/Components/InstallmentCalculator/DependencyInjection/subscriber.xml
+++ b/src/Components/InstallmentCalculator/DependencyInjection/subscriber.xml
@@ -16,8 +16,12 @@
             <tag name="kernel.event_subscriber"/>
         </defaults>
 
-        <service id="Ratepay\RpayPayments\Components\InstallmentCalculator\Subscriber\BuildPaymentSubscriber"/>
-        <service id="Ratepay\RpayPayments\Components\InstallmentCalculator\Subscriber\CheckoutSubscriber"/>
+        <service id="Ratepay\RpayPayments\Components\InstallmentCalculator\Subscriber\BuildPaymentSubscriber">
+            <argument key="$translator" type="service" id="Shopware\Core\Framework\Adapter\Translation\Translator"/>
+        </service>
+        <service id="Ratepay\RpayPayments\Components\InstallmentCalculator\Subscriber\CheckoutSubscriber">
+            <argument key="$translator" type="service" id="Shopware\Core\Framework\Adapter\Translation\Translator"/>
+        </service>
         <service id="Ratepay\RpayPayments\Components\InstallmentCalculator\Subscriber\ProductPageSubscriber">
             <argument key="$logger" id="monolog.logger.ratepay" type="service"/>
             <argument key="$countryRepository" id="country.repository" type="service"/>
diff --git a/src/Components/InstallmentCalculator/Subscriber/BuildPaymentSubscriber.php b/src/Components/InstallmentCalculator/Subscriber/BuildPaymentSubscriber.php
index 039c0e7b..62ebf1c0 100644
--- a/src/Components/InstallmentCalculator/Subscriber/BuildPaymentSubscriber.php
+++ b/src/Components/InstallmentCalculator/Subscriber/BuildPaymentSubscriber.php
@@ -31,13 +31,16 @@
 use Ratepay\RpayPayments\Util\RequestHelper;
 use RuntimeException;
 use Shopware\Core\Checkout\Payment\PaymentMethodEntity;
+use Shopware\Core\Framework\Adapter\Translation\AbstractTranslator;
 use Shopware\Core\Framework\Validation\DataBag\DataBag;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Throwable;
 
 class BuildPaymentSubscriber implements EventSubscriberInterface
 {
     public function __construct(
-        private readonly InstallmentService $installmentService
+        private readonly InstallmentService $installmentService,
+        private readonly AbstractTranslator $translator
     ) {
     }
 
@@ -54,7 +57,9 @@ public function buildPayment(BuildEvent $event): void
         /** @var PaymentRequestData $requestData */
         $requestData = $event->getRequestData();
 
-        if (MethodHelper::isInstallmentMethod($requestData->getTransaction()->getPaymentMethod()->getHandlerIdentifier())) {
+        $paymentMethod = $requestData->getTransaction()->getPaymentMethod();
+
+        if (MethodHelper::isInstallmentMethod($paymentMethod->getHandlerIdentifier())) {
             /** @var Payment $paymentObject */
             $paymentObject = $event->getBuildData();
 
@@ -71,9 +76,15 @@ public function buildPayment(BuildEvent $event): void
             );
             $calcContext->setTotalAmount($paymentObject->getAmount());
             $calcContext->setOrder($requestData->getOrder());
-            $calcContext->setPaymentMethod($requestData->getTransaction()->getPaymentMethod());
-
-            $plan = $this->installmentService->getInstallmentPlanData($calcContext);
+            $calcContext->setPaymentMethod($paymentMethod);
+
+            try {
+                $plan = $this->installmentService->getInstallmentPlanData($calcContext);
+            } catch (Throwable $exception) {
+                throw new RuntimeException($this->translator->trans('checkout.error.RATEPAY_INSTALLMENT_CAN_NOT_BE_LOADED', [
+                    '%method%' => $paymentMethod->getTranslated()['name'] ?? $paymentMethod->getName(),
+                ]), $exception->getCode(), previous: $exception);
+            }
 
             if (PlanHasher::isPlanEqualWithHash($requestedInstallment->get('hash'), $plan)) {
                 throw new Exception('the hash value of the calculated plan does not match the given hash');
diff --git a/src/Components/InstallmentCalculator/Subscriber/CheckoutSubscriber.php b/src/Components/InstallmentCalculator/Subscriber/CheckoutSubscriber.php
index f41977e7..367f4afc 100644
--- a/src/Components/InstallmentCalculator/Subscriber/CheckoutSubscriber.php
+++ b/src/Components/InstallmentCalculator/Subscriber/CheckoutSubscriber.php
@@ -11,19 +11,29 @@
 
 namespace Ratepay\RpayPayments\Components\InstallmentCalculator\Subscriber;
 
+use Psr\Log\LoggerInterface;
 use Ratepay\RpayPayments\Components\Checkout\Event\PaymentDataExtensionBuilt;
 use Ratepay\RpayPayments\Components\InstallmentCalculator\Model\InstallmentCalculatorContext;
 use Ratepay\RpayPayments\Components\InstallmentCalculator\Service\InstallmentService;
 use Ratepay\RpayPayments\Util\MethodHelper;
+use Shopware\Core\Checkout\Cart\Error\Error;
+use Shopware\Core\Checkout\Cart\Error\GenericCartError;
 use Shopware\Core\Checkout\Cart\SalesChannel\CartService;
 use Shopware\Core\Checkout\Order\OrderEntity;
+use Shopware\Core\Framework\Adapter\Translation\AbstractTranslator;
+use Shopware\Core\Framework\Struct\ArrayStruct;
+use Shopware\Storefront\Page\Account\Order\AccountEditOrderPageLoadedEvent;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpFoundation\Session\FlashBagAwareSessionInterface;
+use Throwable;
 
 class CheckoutSubscriber implements EventSubscriberInterface
 {
     public function __construct(
         private readonly InstallmentService $installmentService,
-        private readonly CartService $cartService
+        private readonly CartService $cartService,
+        private readonly LoggerInterface $logger,
+        private readonly AbstractTranslator $translator
     ) {
     }
 
@@ -31,6 +41,7 @@ public static function getSubscribedEvents(): array
     {
         return [
             PaymentDataExtensionBuilt::class => 'buildCheckoutExtension',
+            AccountEditOrderPageLoadedEvent::class => ['onAccountEditOrderPageLoaded', 300],
         ];
     }
 
@@ -45,20 +56,62 @@ public function buildCheckoutExtension(PaymentDataExtensionBuilt $event): void
             $calcContext = (new InstallmentCalculatorContext($salesChannelContext, '', null))
                 ->setPaymentMethodId($paymentMethod->getId())
                 ->setOrder($order);
+            $cart = $this->cartService->getCart($salesChannelContext->getToken(), $salesChannelContext);
 
             if (!$order instanceof OrderEntity) {
-                $calcContext->setTotalAmount($this->cartService->getCart($salesChannelContext->getToken(), $salesChannelContext)->getPrice()->getTotalPrice());
+                $calcContext->setTotalAmount($cart->getPrice()->getTotalPrice());
             }
 
-            $installmentCalculator = $this->installmentService->getInstallmentCalculatorData($calcContext);
+            try {
+                $installmentCalculator = $this->installmentService->getInstallmentCalculatorData($calcContext);
 
-            $calcContext->setCalculationType($installmentCalculator['defaults']['type']);
-            $calcContext->setCalculationValue($installmentCalculator['defaults']['value']);
+                $calcContext->setCalculationType($installmentCalculator['defaults']['type']);
+                $calcContext->setCalculationValue($installmentCalculator['defaults']['value']);
 
-            $vars = $this->installmentService->getInstallmentPlanTwigVars($calcContext);
-            $vars['calculator'] = $installmentCalculator;
+                $vars = $this->installmentService->getInstallmentPlanTwigVars($calcContext);
+                $vars['calculator'] = $installmentCalculator;
+                $extension->offsetSet('installment', $vars);
+            } catch (Throwable $exception) {
+                $this->logger->error('Ratepay installment can not be loaded. ' . $exception->getMessage(), [
+                    'order_id' => $order?->getId(),
+                    'payment_method_id' => $calcContext->getPaymentMethodId(),
+                    'total_amount' => $calcContext->getTotalAmount(),
+                    'calculation_type' => $calcContext->getCalculationType(),
+                    'calculation_value' => $calcContext->getCalculationValue(),
+                ]);
 
-            $extension->offsetSet('installment', $vars);
+                if (!$order instanceof OrderEntity) {
+                    $cart->addErrors(new GenericCartError(
+                        'RATEPAY::INSTALLMENT_CAN_NOT_BE_LOADED',
+                        'error.RATEPAY_INSTALLMENT_CAN_NOT_BE_LOADED',
+                        [
+                            'method' => $paymentMethod->getTranslated()['name'] ?? $paymentMethod->getName(),
+                        ],
+                        Error::LEVEL_ERROR,
+                        true,
+                        false,
+                        true
+                    ));
+                }
+            }
+        }
+    }
+
+    public function onAccountEditOrderPageLoaded(AccountEditOrderPageLoadedEvent $event): void
+    {
+        $paymentMethod = $event->getSalesChannelContext()->getPaymentMethod();
+
+        if (MethodHelper::isInstallmentMethod($paymentMethod->getHandlerIdentifier())) {
+            /** @var ArrayStruct|null $ratepayData */
+            $ratepayData = $event->getPage()->getExtension('ratepay');
+            if ($ratepayData?->get('installment') === null) {
+                $session = $event->getRequest()->getSession();
+                if ($session instanceof FlashBagAwareSessionInterface) {
+                    $session->getFlashbag()->add('danger', $this->translator->trans('checkout.error.RATEPAY_INSTALLMENT_CAN_NOT_BE_LOADED', [
+                        '%method%' => $paymentMethod->getTranslated()['name'] ?? $paymentMethod->getName(),
+                    ]));
+                }
+            }
         }
     }
 }
diff --git a/src/Components/Logging/Subscriber/RequestBuilderFailedSubscriber.php b/src/Components/Logging/Subscriber/RequestBuilderFailedSubscriber.php
index b4253fdc..3cffdf10 100755
--- a/src/Components/Logging/Subscriber/RequestBuilderFailedSubscriber.php
+++ b/src/Components/Logging/Subscriber/RequestBuilderFailedSubscriber.php
@@ -32,7 +32,7 @@ public static function getSubscribedEvents(): array
     public function onRequestBuilderFailed(RequestBuilderFailedEvent $event): void
     {
         // $requestData = $event->getRequestData();
-        $exception = $event->getException();
+        $exception = $event->getThrowable();
         $this->fileLogger->error('RequestBuilder failed', [
             'message' => $exception->getMessage(),
             'trace' => $exception->getTraceAsString(),
diff --git a/src/Components/PaymentHandler/InstallmentPaymentHandler.php b/src/Components/PaymentHandler/InstallmentPaymentHandler.php
index afb75fd0..64ea0393 100644
--- a/src/Components/PaymentHandler/InstallmentPaymentHandler.php
+++ b/src/Components/PaymentHandler/InstallmentPaymentHandler.php
@@ -62,7 +62,7 @@ public function getValidationDefinitions(DataBag $requestDataBag, $baseData): ar
         $ratepayData = RequestHelper::getRatepayData($requestDataBag);
 
         $installmentData = $ratepayData->get('installment');
-        if ($installmentData->get('paymentType') && $installmentData->get('paymentType') === 'DIRECT-DEBIT') {
+        if ($installmentData && $installmentData->get('paymentType') && $installmentData->get('paymentType') === 'DIRECT-DEBIT') {
             $validations = array_merge($validations, $this->getDebitConstraints($baseData));
         }
 
diff --git a/src/Components/RatepayApi/Event/RequestBuilderFailedEvent.php b/src/Components/RatepayApi/Event/RequestBuilderFailedEvent.php
index 7b382ed0..6d34b736 100644
--- a/src/Components/RatepayApi/Event/RequestBuilderFailedEvent.php
+++ b/src/Components/RatepayApi/Event/RequestBuilderFailedEvent.php
@@ -11,23 +11,31 @@
 
 namespace Ratepay\RpayPayments\Components\RatepayApi\Event;
 
-use Exception;
 use Ratepay\RpayPayments\Components\RatepayApi\Dto\AbstractRequestData;
 use Symfony\Contracts\EventDispatcher\Event;
+use Throwable;
 
 class RequestBuilderFailedEvent extends Event
 {
     public function __construct(
-        private readonly Exception $exception,
+        private readonly Throwable $exception,
         private readonly AbstractRequestData $requestData
     ) {
     }
 
-    public function getException(): Exception
+    public function getThrowable(): Throwable
     {
         return $this->exception;
     }
 
+    /**
+     * @deprecated use getThrowable
+     */
+    public function getException(): Throwable
+    {
+        return $this->getThrowable();
+    }
+
     public function getRequestData(): AbstractRequestData
     {
         return $this->requestData;
diff --git a/src/Components/RatepayApi/Service/Request/AbstractRequest.php b/src/Components/RatepayApi/Service/Request/AbstractRequest.php
index 6d369bfa..bb724f00 100644
--- a/src/Components/RatepayApi/Service/Request/AbstractRequest.php
+++ b/src/Components/RatepayApi/Service/Request/AbstractRequest.php
@@ -12,7 +12,6 @@
 namespace Ratepay\RpayPayments\Components\RatepayApi\Service\Request;
 
 use InvalidArgumentException;
-use RatePAY\Exception\ExceptionAbstract;
 use RatePAY\Exception\RequestException;
 use RatePAY\Model\Request\SubModel\Content;
 use RatePAY\Model\Request\SubModel\Head;
@@ -28,6 +27,7 @@
 use Ratepay\RpayPayments\Components\RatepayApi\Factory\HeadFactory;
 use Ratepay\RpayPayments\Exception\RatepayException;
 use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
+use Throwable;
 
 abstract class AbstractRequest
 {
@@ -113,10 +113,10 @@ final public function doRequest(AbstractRequestData $requestData): RequestBuilde
 
         $this->_initRequest($requestData);
 
-        $head = $this->_getRequestHead($requestData);
-        $content = $this->_getRequestContent($requestData);
-
         try {
+            $head = $this->_getRequestHead($requestData);
+            $content = $this->_getRequestContent($requestData);
+
             if ($this->isRequestBlockedByFeatureFlag($requestData)) {
                 throw new RequestException('Request has been blocked by feature flag.');
             }
@@ -126,9 +126,9 @@ final public function doRequest(AbstractRequestData $requestData): RequestBuilde
             if ($this->_subType) {
                 $requestBuilder = $requestBuilder->subtype($this->_subType);
             }
-        } catch (ExceptionAbstract $exception) {
-            $this->eventDispatcher->dispatch(new RequestBuilderFailedEvent($exception, $requestData));
-            throw new RatepayException($exception->getMessage(), $exception->getCode(), $exception);
+        } catch (Throwable $throwable) {
+            $this->eventDispatcher->dispatch(new RequestBuilderFailedEvent($throwable, $requestData));
+            throw new RatepayException($throwable->getMessage(), $throwable->getCode(), $throwable);
         }
 
         $this->eventDispatcher->dispatch(new RequestDoneEvent($requestData, $requestBuilder));
diff --git a/src/Resources/snippet/de_DE/messages.de-DE.json b/src/Resources/snippet/de_DE/messages.de-DE.json
index 68e8aa49..f21c14f1 100644
--- a/src/Resources/snippet/de_DE/messages.de-DE.json
+++ b/src/Resources/snippet/de_DE/messages.de-DE.json
@@ -11,6 +11,7 @@
     "error.VIOLATION::METHOD_NOT_AVAILABLE": "Leider ist eine Bezahlung mit der gewählten Zahlungsart nicht möglich.",
     "error.VIOLATION::RP_MISSING_BANK_ACCOUNT_HOLDER": "Bitte geben Sie den Kontoinhaber an.",
     "error.VIOLATION::RP_INVALID_BANK_ACCOUNT_HOLDER": "Bitte geben Sie einen gültigen Kontoinhaber an.",
+    "checkout.error.RATEPAY_INSTALLMENT_CAN_NOT_BE_LOADED": "Leider kann der Ratenrechner der Zahlungsart %method% nicht geladen und damit die Zahlungsmethode nicht zur Verfügung gestellt werden. Bitte laden Sie die Seite neu, versuchen Sie es später erneut, oder wählen eine andere Zahlungsart.",
     "ratepay": {
         "storefront": {
             "admin-order": {
diff --git a/src/Resources/snippet/en_GB/messages.en-GB.json b/src/Resources/snippet/en_GB/messages.en-GB.json
index b21af6e0..277ab607 100644
--- a/src/Resources/snippet/en_GB/messages.en-GB.json
+++ b/src/Resources/snippet/en_GB/messages.en-GB.json
@@ -11,6 +11,7 @@
     "error.VIOLATION::METHOD_NOT_AVAILABLE": "Unfortunately, it is not possible to use the selected payment method.",
     "error.VIOLATION::RP_MISSING_BANK_ACCOUNT_HOLDER": "Please provide a bank account owner.",
     "error.VIOLATION::RP_INVALID_BANK_ACCOUNT_HOLDER": "Please provide a valid bank account owner.",
+    "checkout.error.RATEPAY_INSTALLMENT_CAN_NOT_BE_LOADED": "Unfortunately the instalment calculator for the payment method %method% could not be loaded and so the payment method could not be provided to you.. Please reload the page, try again later, or choose another payment method.",
     "ratepay": {
         "storefront": {
             "admin-order": {
diff --git a/src/Resources/views/storefront/page/checkout/ratepay/installment.html.twig b/src/Resources/views/storefront/page/checkout/ratepay/installment.html.twig
index 8283bc6b..7f06c5ae 100644
--- a/src/Resources/views/storefront/page/checkout/ratepay/installment.html.twig
+++ b/src/Resources/views/storefront/page/checkout/ratepay/installment.html.twig
@@ -9,5 +9,7 @@
 
 {% block ratepay_checkout_fields %}
     {{ parent() }}
-    {% sw_include '@RatepayPaments/storefront/page/checkout/ratepay/common/installment-calculator.html.twig' %}
+    {% if page.extensions.ratepay.installment.calculator %}
+        {% sw_include '@RatepayPaments/storefront/page/checkout/ratepay/common/installment-calculator.html.twig' %}
+    {% endif %}
 {% endblock %}