Updated to version 11.0.3

CryptoExchange.Net.UnitTests/SystemTextJsonConverterTests.cs

@@ -1,11 +1,15 @@
 using CryptoExchange.Net.Attributes;
+using CryptoExchange.Net.Converters;
 using CryptoExchange.Net.Converters.SystemTextJson;
-using System.Text.Json;
+using CryptoExchange.Net.Objects;
+using CryptoExchange.Net.SharedApis;
+using CryptoExchange.Net.Testing;
+using Newtonsoft.Json.Linq;
 using NUnit.Framework;
 using System;
+using System.Diagnostics;
+using System.Text.Json;
 using System.Text.Json.Serialization;
-using CryptoExchange.Net.Converters;
-using CryptoExchange.Net.SharedApis;
 
 namespace CryptoExchange.Net.UnitTests
 {
@@ -185,6 +189,31 @@ namespace CryptoExchange.Net.UnitTests
             Assert.That(result == expected);
         }
 
+        [Test]
+        public void TestEnumConverterParseNullOnNonNullableOnlyLogsOnce()
+        {
+            LibraryHelpers.StaticLogger = new TraceLogger();
+            var listener = new EnumValueTraceListener();
+            Trace.Listeners.Add(listener);
+            EnumConverter<TestEnum>.Reset();
+            try
+            {
+                Assert.Throws<Exception>(() =>
+                {
+                    var result = JsonSerializer.Deserialize<NotNullableSTJEnumObject>("{\"Value\": null}", SerializerOptions.WithConverters(new SerializationContext()));
+                });
+
+                Assert.DoesNotThrow(() =>
+                {
+                    var result2 = JsonSerializer.Deserialize<NotNullableSTJEnumObject>("{\"Value\": null}", SerializerOptions.WithConverters(new SerializationContext()));
+                });
+            }
+            finally
+            {
+                Trace.Listeners.Remove(listener);
+            }
+        }
+
         [TestCase("1", true)]
         [TestCase("true", true)]
         [TestCase("yes", true)]

CryptoExchange.Net/Converters/SystemTextJson/EnumConverter.cs

@@ -120,13 +120,14 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
         /// <inheritdoc />
         public override T Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {
-            var t = ReadNullable(ref reader, typeToConvert, options, out var isEmptyString);
+            var t = ReadNullable(ref reader, typeToConvert, options, out var isEmptyStringOrNull);
             if (t != null)
                 return t.Value;
             
-            if (isEmptyString && !_unknownValuesWarned.Contains(null))
+            if (isEmptyStringOrNull && !_unknownValuesWarned.Contains(null))
             {
                 // We received an empty string and have no mapping for it, and the property isn't nullable
+                _unknownValuesWarned.Add(null!);
                 LibraryHelpers.StaticLogger?.LogWarning($"Received null or empty enum value, but property type is not a nullable enum. EnumType: {typeof(T).FullName}. If you think {typeof(T).FullName} should be nullable please open an issue on the Github repo");
             }
 
@@ -149,9 +150,9 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             return (T)_undefinedEnumValue;
         }
 
-        private T? ReadNullable(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options, out bool isEmptyString)
+        private T? ReadNullable(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options, out bool isEmptyStringOrNull)
         {
-            isEmptyString = false;
+            isEmptyStringOrNull = false;
             var enumType = typeof(T);
             if (_mappingToEnum == null)
                 CreateMapping();
@@ -167,13 +168,16 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
             };
 
             if (stringValue is null)
+            {
+                isEmptyStringOrNull = true;
                 return null;
+            }
 
             if (!GetValue(enumType, stringValue, out var result))
             {
                 if (string.IsNullOrWhiteSpace(stringValue))
                 {
-                    isEmptyString = true;
+                    isEmptyStringOrNull = true;
                 }
                 else
                 {
@@ -305,6 +309,12 @@ namespace CryptoExchange.Net.Converters.SystemTextJson
 #endif
         }
 
+        internal static void Reset()
+        {
+            _undefinedEnumValue = null;
+            _unknownValuesWarned = new ConcurrentBag<string>();
+        }
+
         /// <summary>
         /// Get the string value for an enum value using the MapAttribute mapping. When multiple values are mapped for a enum entry the first value will be returned
         /// </summary>

CryptoExchange.Net/CryptoExchange.Net.csproj

@@ -6,9 +6,9 @@
     <PackageId>CryptoExchange.Net</PackageId>
     <Authors>JKorf</Authors>
     <Description>CryptoExchange.Net is a base library which is used to implement different cryptocurrency (exchange) API's. It provides a standardized way of implementing different API's, which results in a very similar experience for users of the API implementations.</Description>
-    <PackageVersion>11.0.2</PackageVersion>
-    <AssemblyVersion>11.0.2</AssemblyVersion>
-    <FileVersion>11.0.2</FileVersion>
+    <PackageVersion>11.0.3</PackageVersion>
+    <AssemblyVersion>11.0.3</AssemblyVersion>
+    <FileVersion>11.0.3</FileVersion>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
     <PackageTags>OKX;OKX.Net;Mexc;Mexc.Net;Kucoin;Kucoin.Net;Kraken;Kraken.Net;Huobi;Huobi.Net;CoinEx;CoinEx.Net;Bybit;Bybit.Net;Bitget;Bitget.Net;Bitfinex;Bitfinex.Net;Binance;Binance.Net;CryptoCurrency;CryptoCurrency Exchange;CryptoExchange.Net</PackageTags>
     <RepositoryType>git</RepositoryType>

CryptoExchange.Net/Testing/EnumValueTraceListener.cs

@@ -13,7 +13,7 @@ namespace CryptoExchange.Net.Testing
             if (message.Contains("Cannot map"))
                 throw new Exception("Enum value error: " + message);
 
-            if (message.Contains("Received null enum value"))
+            if (message.Contains("Received null or empty enum value"))
                 throw new Exception("Enum null error: " + message);
         }
 
@@ -25,7 +25,7 @@ namespace CryptoExchange.Net.Testing
             if (message.Contains("Cannot map"))
                 throw new Exception("Enum value error: " + message);
 
-            if (message.Contains("Received null enum value"))
+            if (message.Contains("Received null or empty enum value"))
                 throw new Exception("Enum null error: " + message);
         }
     }

README.md

@@ -68,6 +68,9 @@ Make a one time donation in a crypto currency of your choice. If you prefer to d
 Alternatively, sponsor me on Github using [Github Sponsors](https://github.com/sponsors/JKorf). 
 
 ## Release notes
+* Version 11.0.3 - 30 Mar 2026
+    * Updated Enum converter to only warn once per type for null/empty value for non-nullable enum property
+
 * Version 11.0.2 - 26 Mar 2026
     * Updated SetOptions logic to allow calling on client without credentials