diff --git a/mailpoet/lib/Automation/Engine/Exceptions.php b/mailpoet/lib/Automation/Engine/Exceptions.php
index d36192716c..c05bd91e92 100644
--- a/mailpoet/lib/Automation/Engine/Exceptions.php
+++ b/mailpoet/lib/Automation/Engine/Exceptions.php
@@ -27,6 +27,7 @@ class Exceptions {
   private const WORKFLOW_STRUCTURE_MODIFICATION_NOT_SUPPORTED = 'mailpoet_automation_workflow_structure_modification_not_supported';
   private const WORKFLOW_STRUCTURE_NOT_VALID = 'mailpoet_automation_workflow_structure_not_valid';
   private const WORKFLOW_STEP_MODIFIED_WHEN_UNKNOWN = 'mailpoet_automation_workflow_step_modified_when_unknown';
+  private const WORKFLOW_NOT_VALID = 'mailpoet_automation_workflow_not_valid';
 
   public function __construct() {
     throw new InvalidStateException(
@@ -180,4 +181,12 @@ class Exceptions {
         )
       );
   }
+
+  public static function workflowNotValid(string $detail, array $errors): UnexpectedValueException {
+    return UnexpectedValueException::create()
+      ->withErrorCode(self::WORKFLOW_NOT_VALID)
+      // translators: %s is a detailed information
+      ->withMessage(sprintf(__("Workflow validation failed: %s", 'mailpoet'), $detail))
+      ->withErrors($errors);
+  }
 }
diff --git a/mailpoet/lib/Automation/Engine/Validation/WorkflowRules/ValidStepArgsRule.php b/mailpoet/lib/Automation/Engine/Validation/WorkflowRules/ValidStepArgsRule.php
index ae45745a39..1edf26455f 100644
--- a/mailpoet/lib/Automation/Engine/Validation/WorkflowRules/ValidStepArgsRule.php
+++ b/mailpoet/lib/Automation/Engine/Validation/WorkflowRules/ValidStepArgsRule.php
@@ -3,6 +3,7 @@
 namespace MailPoet\Automation\Engine\Validation\WorkflowRules;
 
 use MailPoet\Automation\Engine\Data\Workflow;
+use MailPoet\Automation\Engine\Exceptions;
 use MailPoet\Automation\Engine\Registry;
 use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowNode;
 use MailPoet\Automation\Engine\Validation\WorkflowGraph\WorkflowNodeVisitor;
@@ -15,6 +16,9 @@ class ValidStepArgsRule implements WorkflowNodeVisitor {
   /** @var Validator */
   private $validator;
 
+  /** @var array<string, array{step_id: string, message: string}> */
+  private $errors = [];
+
   public function __construct(
     Registry $registry,
     Validator $validator
@@ -24,6 +28,7 @@ class ValidStepArgsRule implements WorkflowNodeVisitor {
   }
 
   public function initialize(Workflow $workflow): void {
+    $this->errors = [];
   }
 
   public function visitNode(Workflow $workflow, WorkflowNode $node): void {
@@ -35,10 +40,24 @@ class ValidStepArgsRule implements WorkflowNodeVisitor {
 
     // validate args schema only for active workflows
     if ($workflow->getStatus() !== Workflow::STATUS_ACTIVE) {
+      return;
+    }
+
+    try {
       $this->validator->validate($registryStep->getArgsSchema(), $step->getArgs());
+    } catch (Throwable $e) {
+      $this->errors[$step->getId()] = [
+        'step_id' => $step->getId(),
+        'message' => $e instanceof ValidationException
+          ? $e->getWpError()->get_error_message()
+          : __('Unknown error.', 'mailpoet'),
+      ];
     }
   }
 
   public function complete(Workflow $workflow): void {
+    if ($this->errors) {
+      throw Exceptions::workflowNotValid(__('Some steps have invalid arguments', 'mailpoet'), $this->errors);
+    }
   }
 }