Updated to version 10.2.3

CryptoExchange.Net/Clients/SocketApiClient.cs

@@ -802,7 +802,6 @@ namespace CryptoExchange.Net.Clients
             return new CallResult<HighPerfSocketConnection<TUpdateType>>(socketConnection);
         }
 
-
         /// <summary>
         /// Process an unhandled message
         /// </summary>
@@ -811,6 +810,14 @@ namespace CryptoExchange.Net.Clients
         {
         }
 
+        /// <summary>
+        /// Process an unhandled message
+        /// </summary>
+        /// <param name="connection">The socket connection</param>
+        /// <param name="typeIdentifier">The type as identified</param>
+        /// <param name="data">The data</param>
+        protected internal virtual bool HandleUnhandledMessage(SocketConnection connection, string typeIdentifier, ReadOnlySpan<byte> data) => false;
+
         /// <summary>
         /// Process connect rate limited
         /// </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>10.2.2</PackageVersion>
+    <PackageVersion>10.2.3</PackageVersion>
-    <AssemblyVersion>10.2.2</AssemblyVersion>
+    <AssemblyVersion>10.2.3</AssemblyVersion>
-    <FileVersion>10.2.2</FileVersion>
+    <FileVersion>10.2.3</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/Sockets/Default/SocketConnection.cs

@@ -571,8 +571,12 @@ namespace CryptoExchange.Net.Sockets.Default
 
             if (deserializationType == null)
             {
-                // No handler found for identifier either, can't process
+                if (!ApiClient.HandleUnhandledMessage(this, typeIdentifier, data))
-                _logger.LogWarning("Failed to determine message type for identifier {Identifier}. Data: {Message}", typeIdentifier, Encoding.UTF8.GetString(data.ToArray()));
+                {
+                    // No handler found for identifier either, can't process
+                    _logger.LogWarning("Failed to determine message type for identifier {Identifier}. Data: {Message}", typeIdentifier, Encoding.UTF8.GetString(data.ToArray()));
+                }
+                    
                 return;
             }
             

CryptoExchange.Net/TimeOffsetManager.cs

@@ -113,7 +113,8 @@ namespace CryptoExchange.Net
         /// <param name="api"></param>
         internal static void RegisterRestApi(string api)
         {
-            _lastRestDelays[api] = new RestTimeOffset();
+            if (!_lastRestDelays.ContainsKey(api))
+                _lastRestDelays.TryAdd(api, new RestTimeOffset());
         }
 
         /// <summary>

README.md

@@ -66,6 +66,10 @@ 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 10.2.3 - 14 Jan 2026
+    * Added HandleUnhandledMessage virtual method to SocketApiClient to allow some processing for messages which couldn't be mapped via the normal way
+    * Fixed semaphore exception when creating a new REST client while time sync is in progress on another client
+
 * Version 10.2.2 - 13 Jan 2026
     * Allow the same websocket connection sequence number to be recorded multiple times