diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
index 1941a25..24dc74f 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -2,7 +2,7 @@
 name: Bug report
 about: Create a report to help us improve.
 title: ''
-labels: ''
+labels: 'bug'
 assignees: ''
 
 ---
diff --git a/.github/ISSUE_TEMPLATE/custom.md b/.github/ISSUE_TEMPLATE/custom.md
index fb7bdc3..3e9c17d 100644
--- a/.github/ISSUE_TEMPLATE/custom.md
+++ b/.github/ISSUE_TEMPLATE/custom.md
@@ -2,7 +2,7 @@
 name: Custom issue template
 about: Do you have a question related to the project? Use this template.
 title: ''
-labels: ''
+labels: 'question'
 assignees: ''
 
 ---
diff --git a/.github/ISSUE_TEMPLATE/feature_request.md b/.github/ISSUE_TEMPLATE/feature_request.md
index c76e79f..d3915d5 100644
--- a/.github/ISSUE_TEMPLATE/feature_request.md
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -2,7 +2,7 @@
 name: Feature request
 about: Suggest an idea for this project.
 title: ''
-labels: ''
+labels: 'feature-request'
 assignees: ''
 
 ---
diff --git a/Build/MQTTnet.nuspec b/Build/MQTTnet.nuspec
index 32b02ca..cc9aeaa 100644
--- a/Build/MQTTnet.nuspec
+++ b/Build/MQTTnet.nuspec
@@ -11,14 +11,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports v3.1.0, v3.1.1 and v5.0.0 of the MQTT protocol.</description>
     <releaseNotes>
-* [Core] Converted all pending methods to use async/await.
-* [Core] Fixed an issue when serializing a PubRec (QoS 2) packet for MQTTv5.
-* [Client] Fixed an issue when checking for revoked SSL certificates (thanks to @cslutgen).
-* [RpcClient] Added support for custom topic generation strategies.
-* [Server] Refactoring of server certificate password classes (BREAKING CHANGE!).
-* [Server] Fixed an issue with empty server certificate passwords (thanks to @SeppPenner).
-* [MQTTnet.Server] Added support for certificate passwords (BREAKING CHANGE IN CONFIG!)
-* [MQTTnet.AspNetCore] Fixed an issue with MQTTv5 package serialization (#743, thanks to @JanEggers, @pcbing).
+* [Server] Added support for assigned client IDs (MQTTv5 only) (thanks to @bcrosnier).
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2019</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
diff --git a/Build/build.ps1 b/Build/build.ps1
index 57a60f6..bd193d6 100644
--- a/Build/build.ps1
+++ b/Build/build.ps1
@@ -12,6 +12,13 @@ Write-Host "Nuget version    = $nugetVersion"
 Write-Host "MSBuild path     = $msbuild"
 Write-Host
 
+# Build and execute tests
+&$msbuild ..\Tests\MQTTnet.Core.Tests\MQTTnet.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp2.1" /verbosity:m
+&$msbuild ..\Tests\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp2.1" /verbosity:m
+
+vstest.console.exe ..\Tests\MQTTnet.Core.Tests\bin\Release\netcoreapp2.1\MQTTnet.Tests.dll
+vstest.console.exe ..\Tests\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp2.1\MQTTnet.AspNetCore.Tests.dll
+
 # Build the core library
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
@@ -43,13 +50,6 @@ Write-Host
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 
-# Build and execute tests
-&$msbuild ..\Tests\MQTTnet.Core.Tests\MQTTnet.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp2.1" /verbosity:m
-&$msbuild ..\Tests\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp2.1" /verbosity:m
-
-vstest.console.exe ..\Tests\MQTTnet.Core.Tests\bin\Release\netcoreapp2.1\MQTTnet.Tests.dll
-vstest.console.exe ..\Tests\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp2.1\MQTTnet.AspNetCore.Tests.dll
-
 # Create NuGet packages.
 Invoke-WebRequest -Uri "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe" -OutFile "nuget.exe"
 
diff --git a/Source/MQTTnet.Server/Mqtt/MqttApplicationMessageInterceptor.cs b/Source/MQTTnet.Server/Mqtt/MqttApplicationMessageInterceptor.cs
index 00eb0e7..135a583 100644
--- a/Source/MQTTnet.Server/Mqtt/MqttApplicationMessageInterceptor.cs
+++ b/Source/MQTTnet.Server/Mqtt/MqttApplicationMessageInterceptor.cs
@@ -22,7 +22,8 @@ namespace MQTTnet.Server.Mqtt
         {
             try
             {
-                var sessionItems = (PythonDictionary)context.SessionItems[MqttServerConnectionValidator.WrappedSessionItemsKey];
+                // This might be not set when a message was published by the server instead of a client.
+                context.SessionItems.TryGetValue(MqttServerConnectionValidator.WrappedSessionItemsKey, out var sessionItems);
 
                 var pythonContext = new PythonDictionary
                 {
@@ -50,4 +51,4 @@ namespace MQTTnet.Server.Mqtt
             return Task.CompletedTask;
         }
     }
-}
+}
\ No newline at end of file
diff --git a/Source/MQTTnet/Packets/MqttUserProperty.cs b/Source/MQTTnet/Packets/MqttUserProperty.cs
index eaf9eae..dbfae07 100644
--- a/Source/MQTTnet/Packets/MqttUserProperty.cs
+++ b/Source/MQTTnet/Packets/MqttUserProperty.cs
@@ -13,5 +13,31 @@ namespace MQTTnet.Packets
         public string Name { get; }
 
         public string Value { get; }
+
+        public override int GetHashCode()
+        {
+            return Name.GetHashCode() ^ Value.GetHashCode();
+        }
+
+        public override bool Equals(object other)
+        {
+            return Equals(other as MqttUserProperty);
+        }
+
+        public bool Equals(MqttUserProperty other)
+        {
+            if (other == null)
+            {
+                return false;
+            }
+
+            if (ReferenceEquals(other, this))
+            {
+                return true;
+            }
+
+            return string.Equals(Name, other.Name, StringComparison.Ordinal) &&
+                string.Equals(Value, other.Value, StringComparison.Ordinal);
+        }
     }
 }
diff --git a/Tests/MQTTnet.Core.Tests/MQTTv5/Client_Tests.cs b/Tests/MQTTnet.Core.Tests/MQTTv5/Client_Tests.cs
index c4c7634..59d18fc 100644
--- a/Tests/MQTTnet.Core.Tests/MQTTv5/Client_Tests.cs
+++ b/Tests/MQTTnet.Core.Tests/MQTTv5/Client_Tests.cs
@@ -353,5 +353,52 @@ namespace MQTTnet.Tests.MQTTv5
                 await server.StopAsync();
             }
         }
+
+        [TestMethod]
+        public async Task Publish_And_Receive_New_Properties()
+        {
+            using (var testEnvironment = new TestEnvironment())
+            {
+                await testEnvironment.StartServerAsync();
+
+                var receiver = await testEnvironment.ConnectClientAsync(new MqttClientOptionsBuilder().WithProtocolVersion(MqttProtocolVersion.V500));
+                await receiver.SubscribeAsync("#");
+
+                MqttApplicationMessage receivedMessage = null;
+                receiver.UseApplicationMessageReceivedHandler(c =>
+                {
+                    receivedMessage = c.ApplicationMessage;
+                });
+
+                var sender = await testEnvironment.ConnectClientAsync(new MqttClientOptionsBuilder().WithProtocolVersion(MqttProtocolVersion.V500));
+
+                var applicationMessage = new MqttApplicationMessageBuilder()
+                    .WithTopic("Hello")
+                    .WithPayload("World")
+                    .WithAtMostOnceQoS()
+                    .WithUserProperty("x", "1")
+                    .WithUserProperty("y", "2")
+                    .WithResponseTopic("response")
+                    .WithContentType("text")
+                    .WithMessageExpiryInterval(50)
+                    .WithCorrelationData(new byte[12])
+                    .WithTopicAlias(2)
+                    .Build();
+
+                await sender.PublishAsync(applicationMessage);
+
+                await Task.Delay(500);
+
+                Assert.IsNotNull(receivedMessage);
+                Assert.AreEqual(applicationMessage.Topic, receivedMessage.Topic);
+                Assert.AreEqual(applicationMessage.TopicAlias, receivedMessage.TopicAlias);
+                Assert.AreEqual(applicationMessage.ContentType, receivedMessage.ContentType);
+                Assert.AreEqual(applicationMessage.ResponseTopic, receivedMessage.ResponseTopic);
+                Assert.AreEqual(applicationMessage.MessageExpiryInterval, receivedMessage.MessageExpiryInterval);
+                CollectionAssert.AreEqual(applicationMessage.CorrelationData, receivedMessage.CorrelationData);
+                CollectionAssert.AreEqual(applicationMessage.Payload, receivedMessage.Payload);
+                CollectionAssert.AreEqual(applicationMessage.UserProperties, receivedMessage.UserProperties);
+            }
+        }
     }
 }