diff --git a/src/modules/Elsa.Expressions/Helpers/ObjectConverter.cs b/src/modules/Elsa.Expressions/Helpers/ObjectConverter.cs
index 571397bee..a66d344e6 100644
--- a/src/modules/Elsa.Expressions/Helpers/ObjectConverter.cs
+++ b/src/modules/Elsa.Expressions/Helpers/ObjectConverter.cs
@@ -112,7 +112,13 @@ public static class ObjectConverter
         if (underlyingSourceType == typeof(string) && !underlyingTargetType.IsPrimitive && underlyingTargetType != typeof(object))
         {
             var stringValue = (string)value;
-
+            
+            if (underlyingTargetType == typeof(byte[]))
+            {
+                // Byte arrays are serialized to base64, so in this case, we convert the string back to the requested target type of byte[].
+                return Convert.FromBase64String(stringValue);
+            }
+            
             try
             {
                 var firstChar = stringValue.TrimStart().FirstOrDefault();
diff --git a/src/modules/Elsa.Scheduling/Activities/Delay.cs b/src/modules/Elsa.Scheduling/Activities/Delay.cs
index 1c56d11ee..63981e03d 100644
--- a/src/modules/Elsa.Scheduling/Activities/Delay.cs
+++ b/src/modules/Elsa.Scheduling/Activities/Delay.cs
@@ -78,7 +78,7 @@ public class Delay : Activity, IActivityPropertyDefaultValueProvider
         var resumeAt = clock.UtcNow.Add(timeSpan);
         var payload = new DelayPayload(resumeAt);
 
-        context.JournalData.Add("ResumeAt", resumeAt);
+        context.JournalData["ResumeAt"] = resumeAt;
         context.CreateBookmark(payload);
     }