Fixes

src/Umbraco.Web/PublishedCache/NuCache/DataSource/PropertyData.cs

@@ -5,11 +5,22 @@ namespace Umbraco.Web.PublishedCache.NuCache.DataSource
 {
     internal class PropertyData
     {
+        private string _culture;
+        private string _segment;
+
         [JsonProperty("culture")]
-        public string Culture { get; set; }
+        public string Culture
+        {
+            get => _culture;
+            set => _culture = value ?? throw new ArgumentNullException(nameof(value)); // fixme or fallback to string.Empty? CANNOT be null
+        }
 
         [JsonProperty("seg")]
-        public string Segment { get; set; }
+        public string Segment
+        {
+            get => _segment;
+            set => _segment = value ?? throw new ArgumentNullException(nameof(value)); // fixme or fallback to string.Empty? CANNOT be null
+        }
 
         [JsonProperty("val")]
         public object Value { get; set; }