diff --git a/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs b/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs
index cfd6f0bbe..e0a394dea 100644
--- a/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs
+++ b/src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivity.cs
@@ -23,7 +23,7 @@ public class WorkflowDefinitionActivity : Composite, IInitializable
     public string WorkflowDefinitionId { get; set; } = default!;
 
     /// <summary>
-    /// the latest published version number set by the provider. This is used by tooling to let the user know that a newer version is available.
+    /// The latest published version number set by the provider. This is used by tooling to let the user know that a newer version is available.
     /// </summary>
     public int LatestAvailablePublishedVersion { get; set; }
 
diff --git a/src/modules/Elsa.Workflows.Management/Serialization/Converters/ActivityJsonConverter.cs b/src/modules/Elsa.Workflows.Management/Serialization/Converters/ActivityJsonConverter.cs
index b44039d7a..fdde39057 100644
--- a/src/modules/Elsa.Workflows.Management/Serialization/Converters/ActivityJsonConverter.cs
+++ b/src/modules/Elsa.Workflows.Management/Serialization/Converters/ActivityJsonConverter.cs
@@ -44,6 +44,7 @@ public class ActivityJsonConverter : JsonConverter<IActivity>
         var activityTypeName = GetActivityDetails(activityRoot, out var activityTypeVersion, out var activityDescriptor);
         var notFoundActivityTypeName = ActivityTypeNameHelper.GenerateTypeName<NotFoundActivity>();
 
+        // If the activity type is a NotFoundActivity, try to extract the original activity type name and version.
         if(activityTypeName.Equals(notFoundActivityTypeName) && activityRoot.TryGetProperty("originalActivityJson", out var originalActivityJson))
         {
             activityRoot = JsonDocument.Parse(originalActivityJson.GetString()!).RootElement;
@@ -54,6 +55,7 @@ public class ActivityJsonConverter : JsonConverter<IActivity>
         newOptions.Converters.Add(new InputJsonConverterFactory(_serviceProvider));
         newOptions.Converters.Add(new OutputJsonConverterFactory(_serviceProvider));
 
+        // If the activity type is not found, create a NotFoundActivity instead.
         if (activityDescriptor == null)
         {
             var notFoundContext = new ActivityConstructorContext(activityRoot, newOptions);
@@ -221,10 +223,17 @@ public class ActivityJsonConverter : JsonConverter<IActivity>
             throw new JsonException("Failed to extract activity type property");
 
         var activityTypeName = activityTypeNameElement.GetString()!;
-        
-        activityTypeVersion = activityRoot.TryGetProperty("version", out var activityVersionElement) ? activityVersionElement.GetInt32() : 1;
-        activityDescriptor = _activityRegistry.Find(activityTypeName, activityTypeVersion);
-        activityDescriptor ??= _activityRegistry.Find(activityTypeName);
+
+        if (activityRoot.TryGetProperty("version", out var activityVersionElement))
+        {
+            activityTypeVersion = activityVersionElement.GetInt32();
+            activityDescriptor = _activityRegistry.Find(activityTypeName, activityTypeVersion);
+        }
+        else
+        {
+            activityDescriptor = _activityRegistry.Find(activityTypeName);
+            activityTypeVersion = activityDescriptor?.Version ?? 0;
+        }
         
         return activityTypeName;
     }
diff --git a/src/modules/Elsa.Workflows.Management/Serialization/SerializationOptionsConfigurator.cs b/src/modules/Elsa.Workflows.Management/Serialization/SerializationOptionsConfigurator.cs
index f038bfe3c..70ab26f1c 100644
--- a/src/modules/Elsa.Workflows.Management/Serialization/SerializationOptionsConfigurator.cs
+++ b/src/modules/Elsa.Workflows.Management/Serialization/SerializationOptionsConfigurator.cs
@@ -5,15 +5,22 @@ using Microsoft.Extensions.DependencyInjection;
 
 namespace Elsa.Workflows.Management.Serialization;
 
+/// <summary>
+/// Configures the JSON serialization options with support for serializing and deserializing activities and expressions.
+/// </summary>
 public class SerializationOptionsConfigurator : ISerializationOptionsConfigurator
 {
     private readonly IServiceProvider _serviceProvider;
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SerializationOptionsConfigurator"/> class.
+    /// </summary>
     public SerializationOptionsConfigurator(IServiceProvider serviceProvider)
     {
         _serviceProvider = serviceProvider;
     }
 
+    /// <inheritdoc />
     public void Configure(JsonSerializerOptions options)
     {
         options.Converters.Add(Create<ActivityJsonConverterFactory>());