v4.3.0.858

• [Client] Fixed PlatformNotSupportedException when using Blazor (#1755, thanks to @Nickztar).
• [Client] Added hot reload of client certificates (#1781).
• [Client] Added several new option builders and aligned usage (#1781, BREAKING CHANGE!).
• [Client] Added support for RemoteCertificateValidationCallback for .NET 4.5.2, 4.6.1 and 4.8 (#1806, thanks to @troky).
• [Client] Fixed wrong logging of obsolete feature when connection was not successful (#1801, thanks to @ramonsmits).
• [Client] Fixed NullReferenceException when performing several actions when not connected (#1800, thanks to @ramonsmits).
• [RpcClient] Added support for passing custom parameters to topic generation context (#1798, thanks to @Temppus).
• [Server] Fixed NullReferenceException in retained messages management (#1762, thanks to @logicaloud).
• [Server] Exposed new option which allows disabling packet fragmentation (#1753).
• [Server] Expired sessions will no longer be used when a client connects (#1756).
• [Server] Fixed an issue in connection handling for ASP.NET connections (#1819, thanks to @CZEMacLeod).

v4.2.1.781

• [Core] Add validation of maximum string lengths (#1718).
• [Core] Added .NET 4.8 builds (#1729).
• [Core] Exposed more details of DISCONNECT packet in log (#1729).
• [Core] Fixed ArgumentNullException in ConvertPayloadToString (#1745, thanks to @ramonsmits).
• [Client] Added overloads for setting packet payload and will payload (#1720).
• [Client] The proper connect result is now exposed in the Disconnected event when authentication fails (#1139).
• [Client] Exposed UseDefaultCredentials and more for Web Socket options and proxy options (#1734, thanks to @impworks).
• [Client] Exposed more TLS options (#1729).
• [Client] Fixed wrong return code conversion (#1729).
• [Client] Added an option to avoid throwing an exception when the server returned a proper non success (but valid) response (#1681).
• [Server] Improved performance by changing internal locking strategy for subscriptions (#1716, thanks to @zeheng).
• [Server] Fixed exceptions when clients are connecting and disconnecting very fast while accessing the client status for connection validation (#1742).
• [Server] Exposed more properties in ClientConnectedEventArgs (#1738).

4.2.0.706

• [Core] Added net7.0 builds (#1635, thanks to @YAJeff).
• [Core] Added support for payload segments (#1585, thanks to @xljiulang)
• [Client] Added support for passing MQTT v5 options (User properties etc.) for disconnects.
• [Client] An internal exception is no longer caught silently when calling DisconnectAsync to indicate that the disconnect is not clean (BREAKING CHANGE).
• [Client] MQTTv5 features are now checked and an exception is thrown if they are used when using protocol version 3.1.1 and lower. These checks can be disabled in client options. (BREAKING CHANGE!).
• [Client] Added support for disabling packet fragmentation (required for i.e. AWS, #1690, thanks to @logicaloud).
• [Client] Added new overloads for options builder.
• [Client] Renamed InspectPackage to InspectPacketAsync (BREAKING CHANGE).
• [ManagedClient] Exposed added and removed topics in ManagedProcessFailedEventArgs (#1678, thanks to @scottbrogden-iheartmedia).
• [Server] Exposed MQTT v5 sent properties from the affected client in ClientDisconnectedAsync event.
• [Server] Fixed wrong client ID passed to InterceptingUnsubscriptionEventArgs (#1631, thanks to @ghord).
• [Server] Exposed socket settings for TCP keep alive in TCP options (#1544).
• [Server] Exposed server session items at server level and allow custom session items for injected application messages (#1638).
• [Server] Improved performance for retained message handling when subscribing using "DoNotSendOnSubscribe" or "SendAtSubscribeIfNewSubscriptionOnly" (#1661, thanks to @Int32Overflow).
• [Server] Added support for changing the used TLS certificate while the server is running (#1652, thanks to @YAJeff). The certificate provider will now be invoked for every new connection!
• [Server] Added a new API method which allows reading a single retained message without the need to processing the entire set of retained messages (#1659).
• [Server] Added a new event (InterceptingClientEnqueueAsync) which allows intercepting when an application message is enqueued for a client (#1648).
• [Server] Fixed race condition when handling connections which leads to stopped message transfers (#1677, thanks to @RazvanEmilR).
• [Server] Fixed not delivered packets to other sessions if the InterceptingClientEnqueueEvent is used and accepting the packet is denied (#1685, thanks to @RossHNPC).
• [Server] Added missing user properties to subscribe and unsubscribe interceptor (#1702).

v4.1.4.563

• [Core] Fixed a memory leak in AsyncSignal implementation (#1586, thanks to @mario-zelger).
• [Core] Fixed an issue with bounds handling in MqttBufferReader (#1593).
• [Core] Performance improvements and reduced memory usage due to improved buffer copies (#1599, thanks to @xljiulang).
• [Server] Fix not properly reset statistics (#1587, thanks to @damikun).
• [Server] Now using an empty string as the sender client ID for injected application messages (#1583, thanks to @xljiulang).
• [Server] Improved memory usage for ASP.NET connections (#1582, thanks to @xljiulang).
• [Server] Improved memory usage and performance for ASP.NET integration (#1596, thanks to @xljiulang).
• [Server] Add support for interception of will messages (#1613).
• [Server] Fixed wrong topic filter detections (#1615, thanks to @logicaloud).

v4.1.3.436

• [Core] Fixed several dead locks by implementing a new async signal (#1552)
• [Client] All waiting tasks will now fail when the client connection gets closed. This fixes several freezes (#1561)
• [ManagedClient] The topic is no longer declared as invalid if a topic alias is used (#1395)
• [Server] Fixed duplicated invocation of the event ClientAcknowledgedPublishPacketAsync for QoS level 2 (#1550)
• [Server] Fixed issue in upgrading and downgrading of QoS levels for subscriptions and retained messages (#1560)
• [Server] Fixed memory leak when old sessions are discarded (#1553)
• [Server] When using MQTTv5 the reason code NoMatchingSubscribers is returned when no client is subscribed to a published topic (#802)
• [Server] Fix sending of duplicate messages with QoS > 0 when session is recovered, and session is reused (#1546)

v4.1.2.350

• [Core] Fixed dead lock and race conditions in new AsyncLock implementation (#1542).
• [Client] Fixed connection freeze when using Xamarin etc.

v4.1.1.318

• [Core] MQTT Packets being sent over web socket transport are now setting the web socket frame boundaries correctly (#1499).
• [Core] Add support for attaching and detaching events from different threads.
• [Core] Fixed a deadlock in AsyncLock implementation (#1520).
• [Client] Keep alive mechanism now uses the configured timeout value from the options (thanks to @Stannieman, #1495).
• [Client] The PingAsync will fallback to the timeout specified in the client options when the cancellation token cannot be cancelled.
• [Server] A DISCONNECT packet is no longer sent to MQTT clients < 5.0.0 (thanks to @logicaloud, #1506).
• [Server] Improved "take over" process handling.

v4.1.0.247

• [Core] Fixed not working removal of event handlers from async events (#1479).
• [Client] Added support for passing the local endpoint (network card) which should be used (#1311).
• [Client] Exposed PackageIdentifier in MqttApplicationMessageReceivedEventArgs (thanks to @koepalex, #1466).
• [Server] Added a new event (ClientAcknowledgedPublishPacketAsync) which is fired whenever a client acknowledges a PUBLISH packet (QoS 1 and 2, #487).
• [Server] Exposed channel adapter (HTTP context etc.) in connection validation (#1125).
• [Server] The event InterceptingPublishAsync is now also called for injected application messages (#1470).
• [Server] Exposed session items in multiple events (#1291).

v4.0.2.221

• [Core] Updated nuget packages.
• [Core] The option IgnoreCertificateChainErrors is now respected (thanks to @GodVenn, #1447).
• [ManagedClient] The managed client now sends the entire topic filter including new MQTTv5 properties when subscribing.
• [ManagedClient] Fixed wrong firing of ApplicationMessageSkippedAsync event (thanks to @quackgizmo, #1460).
• [Server] Fixed reporting of MaximumQoS in ConnAck packet (MQTTv5 only) (#1442).
• [Server] Fix cross thread issue in session message storage for QoS 1 and 2.
• [Server] The event ClientSubscribedTopicAsync is now fired after the subscription is completely processed internally (#1435).
• [Server] Improved CPU usage on lower end machines (#788).

v4.0.1.184

• [Client] Added the flag try_private (MQTT 3.1.1 Bridge) to client options (#1413).
• [Client] Fixed MQTTv5 protocol violation in PUBLISH packets (#1423).
• [Client] Added missing "WithWill..." methods in MqttClientOptionsBuilder.
• [ManagedClient] Fixed wrong event args type for connected and disconnected events (#1432).
• [Server] Fixed wrong handling of retained messages with QoS > 0 (#1434).
• [Server] Connections with try_private flag (MQTT 3.1.1 Bridge) are now accepted (#1413).