diff --git a/ArchiSteamFarm/ArchiWebHandler.cs b/ArchiSteamFarm/ArchiWebHandler.cs
index 35247a49e..d63948a38 100644
--- a/ArchiSteamFarm/ArchiWebHandler.cs
+++ b/ArchiSteamFarm/ArchiWebHandler.cs
@@ -230,7 +230,10 @@ namespace ArchiSteamFarm {
 						asset.RealAppID = description.RealAppID;
 						asset.Type = description.Type;
 						asset.Rarity = description.Rarity;
-						asset.AdditionalProperties = description.AdditionalProperties;
+
+						if (description.AdditionalProperties != null) {
+							asset.AdditionalProperties = description.AdditionalProperties.ToImmutableDictionary();
+						}
 
 						assetIDs.Add(asset.AssetID);
 
diff --git a/ArchiSteamFarm/BotConfig.cs b/ArchiSteamFarm/BotConfig.cs
index d9473727a..e353d27bc 100644
--- a/ArchiSteamFarm/BotConfig.cs
+++ b/ArchiSteamFarm/BotConfig.cs
@@ -151,7 +151,12 @@ namespace ArchiSteamFarm {
 		public ulong SteamMasterClanID { get; private set; } = DefaultSteamMasterClanID;
 
 		[JsonExtensionData]
-		internal Dictionary<string, JToken> AdditionalProperties { get; set; }
+		internal Dictionary<string, JToken> AdditionalProperties {
+			get;
+
+			[UsedImplicitly]
+			set;
+		}
 
 		internal string DecryptedSteamPassword {
 			get {
diff --git a/ArchiSteamFarm/GlobalConfig.cs b/ArchiSteamFarm/GlobalConfig.cs
index e1e7214c8..73f4e28ac 100644
--- a/ArchiSteamFarm/GlobalConfig.cs
+++ b/ArchiSteamFarm/GlobalConfig.cs
@@ -197,7 +197,12 @@ namespace ArchiSteamFarm {
 		public ProtocolTypes SteamProtocols { get; private set; } = DefaultSteamProtocols;
 
 		[JsonExtensionData]
-		internal Dictionary<string, JToken> AdditionalProperties { get; set; }
+		internal Dictionary<string, JToken> AdditionalProperties {
+			get;
+
+			[UsedImplicitly]
+			set;
+		}
 
 		internal bool IsWebProxyPasswordSet { get; private set; }
 		internal bool ShouldSerializeEverything { private get; set; } = true;
diff --git a/ArchiSteamFarm/Json/Steam.cs b/ArchiSteamFarm/Json/Steam.cs
index 680113852..a6b686120 100644
--- a/ArchiSteamFarm/Json/Steam.cs
+++ b/ArchiSteamFarm/Json/Steam.cs
@@ -72,7 +72,7 @@ namespace ArchiSteamFarm.Json {
 			public uint RealAppID { get; internal set; }
 
 			[PublicAPI]
-			public ImmutableHashSet<Tag> Tags { get; internal set; } = ImmutableHashSet<Tag>.Empty;
+			public ImmutableHashSet<Tag> Tags { get; internal set; }
 
 			[PublicAPI]
 			public bool Tradable { get; internal set; }
@@ -511,13 +511,20 @@ namespace ArchiSteamFarm.Json {
 			private InventoryResponse() { }
 
 			internal sealed class Description {
-#pragma warning disable 649
 				[JsonExtensionData]
-				internal readonly ImmutableDictionary<string, JToken> AdditionalProperties;
-#pragma warning restore 649
+				internal Dictionary<string, JToken> AdditionalProperties {
+					get;
+
+					[UsedImplicitly]
+					set;
+				}
 
 				internal Asset.ERarity Rarity {
 					get {
+						if (Tags == null) {
+							return Asset.ERarity.Unknown;
+						}
+
 						foreach (Asset.Tag tag in Tags) {
 							switch (tag.Identifier) {
 								case "droprate":
@@ -544,6 +551,10 @@ namespace ArchiSteamFarm.Json {
 
 				internal uint RealAppID {
 					get {
+						if (Tags == null) {
+							return 0;
+						}
+
 						foreach (Asset.Tag tag in Tags) {
 							switch (tag.Identifier) {
 								case "Game":
@@ -571,6 +582,10 @@ namespace ArchiSteamFarm.Json {
 
 				internal Asset.EType Type {
 					get {
+						if (Tags == null) {
+							return Asset.EType.Unknown;
+						}
+
 						Asset.EType type = Asset.EType.Unknown;
 
 						foreach (Asset.Tag tag in Tags) {
@@ -584,10 +599,8 @@ namespace ArchiSteamFarm.Json {
 										default:
 											ASF.ArchiLogger.LogGenericError(string.Format(Strings.WarningUnknownValuePleaseReport, nameof(tag.Value), tag.Value));
 
-											break;
+											return Asset.EType.Unknown;
 									}
-
-									break;
 								case "item_class":
 									switch (tag.Value) {
 										case "item_class_2":
@@ -596,7 +609,7 @@ namespace ArchiSteamFarm.Json {
 												type = Asset.EType.TradingCard;
 											}
 
-											break;
+											continue;
 										case "item_class_3":
 											return Asset.EType.ProfileBackground;
 										case "item_class_4":
@@ -620,10 +633,8 @@ namespace ArchiSteamFarm.Json {
 										default:
 											ASF.ArchiLogger.LogGenericError(string.Format(Strings.WarningUnknownValuePleaseReport, nameof(tag.Value), tag.Value));
 
-											break;
+											return Asset.EType.Unknown;
 									}
-
-									break;
 							}
 						}
 
@@ -639,7 +650,7 @@ namespace ArchiSteamFarm.Json {
 				internal bool Marketable { get; set; }
 
 				[JsonProperty(PropertyName = "tags", Required = Required.DisallowNull)]
-				internal ImmutableHashSet<Asset.Tag> Tags { get; set; } = ImmutableHashSet<Asset.Tag>.Empty;
+				internal ImmutableHashSet<Asset.Tag> Tags { get; set; }
 
 				internal bool Tradable { get; set; }