diff --git a/SocketBase/Logging/NLogLog.cs b/SocketBase/Logging/NLogLog.cs
index 1451995..e154bd5 100644
--- a/SocketBase/Logging/NLogLog.cs
+++ b/SocketBase/Logging/NLogLog.cs
@@ -156,7 +156,7 @@ public void Error(object message)
         /// <param name="exception">The exception.</param>
         public void Error(object message, Exception exception)
         {
-            throw new Exception("You have called a method that has not implemented this.");
+            Log.Error($"msg:{message}, exception:{exception.ToString()}");
         }
 
         /// <summary>
diff --git a/SocketEngine/TcpSocketServerBase.cs b/SocketEngine/TcpSocketServerBase.cs
index 54b0329..7ef5a44 100644
--- a/SocketEngine/TcpSocketServerBase.cs
+++ b/SocketEngine/TcpSocketServerBase.cs
@@ -61,7 +61,7 @@ protected IAppSession CreateSession(Socket client, ISocketSession session)
                 client.IOControl(IOControlCode.KeepAliveValues, m_KeepAliveOptionValues, m_KeepAliveOptionOutValues);
 
             client.NoDelay = m_NoDelay;
-            client.LingerState = new LingerOption(enable:true, seconds:0);
+            client.LingerState = new LingerOption(enable:false, seconds:0); // socket 종료하면 즉시 제거한다.
             //client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontLinger, true); //닷넷코어에서 사용 불가
 
             return this.AppServer.CreateAppSession(session);
diff --git a/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.dll b/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.dll
index 0286284..52ba777 100644
Binary files a/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.dll and b/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.dll differ
diff --git a/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.pdb b/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.pdb
index 3bd11e6..e13fb6e 100644
Binary files a/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.pdb and b/Tutorials/00_superSocketLite_libs/netstandard2.0/SuperSocket.SocketBase.pdb differ
diff --git a/Tutorials/EchoServerEx/EchoServerEx.csproj b/Tutorials/EchoServerEx/EchoServerEx.csproj
index 4ffaa37..9cd5df7 100644
--- a/Tutorials/EchoServerEx/EchoServerEx.csproj
+++ b/Tutorials/EchoServerEx/EchoServerEx.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
@@ -24,15 +24,9 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Reference Include="SuperSocket.Common">
-      <HintPath>..\00_superSocketLite_libs\netstandard2.0\SuperSocket.Common.dll</HintPath>
-    </Reference>
-    <Reference Include="SuperSocket.SocketBase">
-      <HintPath>..\00_superSocketLite_libs\netstandard2.0\SuperSocket.SocketBase.dll</HintPath>
-    </Reference>
-    <Reference Include="SuperSocket.SocketEngine">
-      <HintPath>..\00_superSocketLite_libs\netstandard2.0\SuperSocket.SocketEngine.dll</HintPath>
-    </Reference>
+    <ProjectReference Include="..\..\Common\SuperSocket.Common.csproj" />
+    <ProjectReference Include="..\..\SocketBase\SuperSocket.SocketBase.csproj" />
+    <ProjectReference Include="..\..\SocketEngine\SuperSocket.SocketEngine.csproj" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/Tutorials/EchoServerEx/EchoServerEx.sln b/Tutorials/EchoServerEx/EchoServerEx.sln
index 6cd762c..05d81f4 100644
--- a/Tutorials/EchoServerEx/EchoServerEx.sln
+++ b/Tutorials/EchoServerEx/EchoServerEx.sln
@@ -1,10 +1,18 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
-VisualStudioVersion = 15.0.28307.168
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.28803.202
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "EchoServerEx", "EchoServerEx.csproj", "{191FCBF6-F42D-401C-9173-F8E096775177}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "SuperSocket", "SuperSocket", "{6277710D-1BD5-4A02-9BF1-7B4B246AED5F}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SuperSocket.Common", "..\..\Common\SuperSocket.Common.csproj", "{82F5EC58-2D97-434B-A78F-49666A79C4A2}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SuperSocket.SocketBase", "..\..\SocketBase\SuperSocket.SocketBase.csproj", "{7E048E3B-2BCE-481B-A37F-13EED4985BF1}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SuperSocket.SocketEngine", "..\..\SocketEngine\SuperSocket.SocketEngine.csproj", "{3CA4886E-FFD8-4342-BAE2-3F97B8E003B0}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -15,10 +23,27 @@ Global
 		{191FCBF6-F42D-401C-9173-F8E096775177}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{191FCBF6-F42D-401C-9173-F8E096775177}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{191FCBF6-F42D-401C-9173-F8E096775177}.Release|Any CPU.Build.0 = Release|Any CPU
+		{82F5EC58-2D97-434B-A78F-49666A79C4A2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{82F5EC58-2D97-434B-A78F-49666A79C4A2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{82F5EC58-2D97-434B-A78F-49666A79C4A2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{82F5EC58-2D97-434B-A78F-49666A79C4A2}.Release|Any CPU.Build.0 = Release|Any CPU
+		{7E048E3B-2BCE-481B-A37F-13EED4985BF1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7E048E3B-2BCE-481B-A37F-13EED4985BF1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7E048E3B-2BCE-481B-A37F-13EED4985BF1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7E048E3B-2BCE-481B-A37F-13EED4985BF1}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3CA4886E-FFD8-4342-BAE2-3F97B8E003B0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3CA4886E-FFD8-4342-BAE2-3F97B8E003B0}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3CA4886E-FFD8-4342-BAE2-3F97B8E003B0}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3CA4886E-FFD8-4342-BAE2-3F97B8E003B0}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{82F5EC58-2D97-434B-A78F-49666A79C4A2} = {6277710D-1BD5-4A02-9BF1-7B4B246AED5F}
+		{7E048E3B-2BCE-481B-A37F-13EED4985BF1} = {6277710D-1BD5-4A02-9BF1-7B4B246AED5F}
+		{3CA4886E-FFD8-4342-BAE2-3F97B8E003B0} = {6277710D-1BD5-4A02-9BF1-7B4B246AED5F}
+	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {A2804119-9424-4C9F-9A29-D72B9FA068E9}
 	EndGlobalSection
diff --git a/Tutorials/EchoServerEx/MainServer.cs b/Tutorials/EchoServerEx/MainServer.cs
index e08d994..60e64be 100644
--- a/Tutorials/EchoServerEx/MainServer.cs
+++ b/Tutorials/EchoServerEx/MainServer.cs
@@ -100,7 +100,7 @@ void OnClosed(NetworkSession session, CloseReason reason)
 
         void RequestReceived(NetworkSession session, EFBinaryRequestInfo reqInfo)
         {
-            MainLogger.Info($"세션 번호 {session.SessionID}, 받은 데이터 크기: {reqInfo.Body.Length}");
+            //MainLogger.Info($"세션 번호 {session.SessionID}, 받은 데이터 크기: {reqInfo.Body.Length}");
             
             var PacketID = reqInfo.PacketID;