diff --git a/Tests/IPAddressTests/IPAddressTests.nfproj b/Tests/IPAddressTests/IPAddressTests.nfproj
index 86b7c84..0681317 100644
--- a/Tests/IPAddressTests/IPAddressTests.nfproj
+++ b/Tests/IPAddressTests/IPAddressTests.nfproj
@@ -37,7 +37,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
-      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.52\lib\netnano1.0\mscorlib.dll</HintPath>
+      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.63\lib\netnano1.0\mscorlib.dll</HintPath>
     </Reference>
     <Reference Include="nanoFramework.System.Text, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
       <HintPath>..\..\packages\nanoFramework.System.Text.2.0.0-preview.23\lib\netnano1.0\nanoFramework.System.Text.dll</HintPath>
diff --git a/Tests/IPAddressTests/packages.config b/Tests/IPAddressTests/packages.config
index f1d5fea..753e0fc 100644
--- a/Tests/IPAddressTests/packages.config
+++ b/Tests/IPAddressTests/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" targetFramework="netnano1.0" />
+  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="2.0.0-preview.22" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Text" version="2.0.0-preview.23" targetFramework="netnano1.0" />
   <package id="nanoFramework.TestFramework" version="4.0.0-preview.64" targetFramework="netnano1.0" developmentDependency="true" />
diff --git a/Tests/IPAddressTests/packages.lock.json b/Tests/IPAddressTests/packages.lock.json
index 0ea0424..78930df 100644
--- a/Tests/IPAddressTests/packages.lock.json
+++ b/Tests/IPAddressTests/packages.lock.json
@@ -4,9 +4,9 @@
     ".NETnanoFramework,Version=v1.0": {
       "nanoFramework.CoreLibrary": {
         "type": "Direct",
-        "requested": "[2.0.0-preview.52, 2.0.0-preview.52]",
-        "resolved": "2.0.0-preview.52",
-        "contentHash": "cV9JEhoc2OV/UL602i5xmEwQpnn/gzVMlDTAIAMRxCNwBKNYLO9U50OkJykpGnO2SULTsmvFqQWEGZiuANBZHw=="
+        "requested": "[2.0.0-preview.63, 2.0.0-preview.63]",
+        "resolved": "2.0.0-preview.63",
+        "contentHash": "M2qEbjY8Uh5jpgrqDD7vJf2YXk3CmGbTHkb/t6w4F/aNyetOYk0LyekdwUSF0kZ+gTNMH/y6CTHBbJfgtMbIeA=="
       },
       "nanoFramework.System.IO.Streams": {
         "type": "Direct",
diff --git a/Tests/NetworkHelperTests/NetworkHelperTests.nfproj b/Tests/NetworkHelperTests/NetworkHelperTests.nfproj
index 633937e..1fa55e3 100644
--- a/Tests/NetworkHelperTests/NetworkHelperTests.nfproj
+++ b/Tests/NetworkHelperTests/NetworkHelperTests.nfproj
@@ -46,7 +46,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
-      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.52\lib\netnano1.0\mscorlib.dll</HintPath>
+      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.63\lib\netnano1.0\mscorlib.dll</HintPath>
     </Reference>
     <Reference Include="nanoFramework.System.Text, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
       <HintPath>..\..\packages\nanoFramework.System.Text.2.0.0-preview.23\lib\netnano1.0\nanoFramework.System.Text.dll</HintPath>
diff --git a/Tests/NetworkHelperTests/packages.config b/Tests/NetworkHelperTests/packages.config
index 8342be9..219a9d1 100644
--- a/Tests/NetworkHelperTests/packages.config
+++ b/Tests/NetworkHelperTests/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" targetFramework="netnano1.0" />
+  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="2.0.0-preview.22" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Text" version="2.0.0-preview.23" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Threading" version="2.0.0-preview.14" targetFramework="netnano1.0" />
diff --git a/Tests/NetworkHelperTests/packages.lock.json b/Tests/NetworkHelperTests/packages.lock.json
index e0b67fa..4cb4667 100644
--- a/Tests/NetworkHelperTests/packages.lock.json
+++ b/Tests/NetworkHelperTests/packages.lock.json
@@ -4,9 +4,9 @@
     ".NETnanoFramework,Version=v1.0": {
       "nanoFramework.CoreLibrary": {
         "type": "Direct",
-        "requested": "[2.0.0-preview.52, 2.0.0-preview.52]",
-        "resolved": "2.0.0-preview.52",
-        "contentHash": "cV9JEhoc2OV/UL602i5xmEwQpnn/gzVMlDTAIAMRxCNwBKNYLO9U50OkJykpGnO2SULTsmvFqQWEGZiuANBZHw=="
+        "requested": "[2.0.0-preview.63, 2.0.0-preview.63]",
+        "resolved": "2.0.0-preview.63",
+        "contentHash": "M2qEbjY8Uh5jpgrqDD7vJf2YXk3CmGbTHkb/t6w4F/aNyetOYk0LyekdwUSF0kZ+gTNMH/y6CTHBbJfgtMbIeA=="
       },
       "nanoFramework.System.IO.Streams": {
         "type": "Direct",
diff --git a/Tests/SocketTests/SocketTests.nfproj b/Tests/SocketTests/SocketTests.nfproj
index e475bbf..1d05832 100644
--- a/Tests/SocketTests/SocketTests.nfproj
+++ b/Tests/SocketTests/SocketTests.nfproj
@@ -44,7 +44,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
-      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.52\lib\netnano1.0\mscorlib.dll</HintPath>
+      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.63\lib\netnano1.0\mscorlib.dll</HintPath>
     </Reference>
     <Reference Include="nanoFramework.System.Text, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
       <HintPath>..\..\packages\nanoFramework.System.Text.2.0.0-preview.23\lib\netnano1.0\nanoFramework.System.Text.dll</HintPath>
diff --git a/Tests/SocketTests/packages.config b/Tests/SocketTests/packages.config
index 8342be9..219a9d1 100644
--- a/Tests/SocketTests/packages.config
+++ b/Tests/SocketTests/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" targetFramework="netnano1.0" />
+  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="2.0.0-preview.22" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Text" version="2.0.0-preview.23" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Threading" version="2.0.0-preview.14" targetFramework="netnano1.0" />
diff --git a/Tests/SocketTests/packages.lock.json b/Tests/SocketTests/packages.lock.json
index e0b67fa..4cb4667 100644
--- a/Tests/SocketTests/packages.lock.json
+++ b/Tests/SocketTests/packages.lock.json
@@ -4,9 +4,9 @@
     ".NETnanoFramework,Version=v1.0": {
       "nanoFramework.CoreLibrary": {
         "type": "Direct",
-        "requested": "[2.0.0-preview.52, 2.0.0-preview.52]",
-        "resolved": "2.0.0-preview.52",
-        "contentHash": "cV9JEhoc2OV/UL602i5xmEwQpnn/gzVMlDTAIAMRxCNwBKNYLO9U50OkJykpGnO2SULTsmvFqQWEGZiuANBZHw=="
+        "requested": "[2.0.0-preview.63, 2.0.0-preview.63]",
+        "resolved": "2.0.0-preview.63",
+        "contentHash": "M2qEbjY8Uh5jpgrqDD7vJf2YXk3CmGbTHkb/t6w4F/aNyetOYk0LyekdwUSF0kZ+gTNMH/y6CTHBbJfgtMbIeA=="
       },
       "nanoFramework.System.IO.Streams": {
         "type": "Direct",
diff --git a/Tests/SslStreamTests/SslStreamTests.nfproj b/Tests/SslStreamTests/SslStreamTests.nfproj
index 72d34a3..326e1a0 100644
--- a/Tests/SslStreamTests/SslStreamTests.nfproj
+++ b/Tests/SslStreamTests/SslStreamTests.nfproj
@@ -43,7 +43,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="mscorlib">
-      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.52\lib\netnano1.0\mscorlib.dll</HintPath>
+      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.63\lib\netnano1.0\mscorlib.dll</HintPath>
     </Reference>
     <Reference Include="nanoFramework.System.Text">
       <HintPath>..\..\packages\nanoFramework.System.Text.2.0.0-preview.23\lib\netnano1.0\nanoFramework.System.Text.dll</HintPath>
diff --git a/Tests/SslStreamTests/packages.config b/Tests/SslStreamTests/packages.config
index 8342be9..219a9d1 100644
--- a/Tests/SslStreamTests/packages.config
+++ b/Tests/SslStreamTests/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" targetFramework="netnano1.0" />
+  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="2.0.0-preview.22" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Text" version="2.0.0-preview.23" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Threading" version="2.0.0-preview.14" targetFramework="netnano1.0" />
diff --git a/Tests/SslStreamTests/packages.lock.json b/Tests/SslStreamTests/packages.lock.json
index e0b67fa..4cb4667 100644
--- a/Tests/SslStreamTests/packages.lock.json
+++ b/Tests/SslStreamTests/packages.lock.json
@@ -4,9 +4,9 @@
     ".NETnanoFramework,Version=v1.0": {
       "nanoFramework.CoreLibrary": {
         "type": "Direct",
-        "requested": "[2.0.0-preview.52, 2.0.0-preview.52]",
-        "resolved": "2.0.0-preview.52",
-        "contentHash": "cV9JEhoc2OV/UL602i5xmEwQpnn/gzVMlDTAIAMRxCNwBKNYLO9U50OkJykpGnO2SULTsmvFqQWEGZiuANBZHw=="
+        "requested": "[2.0.0-preview.63, 2.0.0-preview.63]",
+        "resolved": "2.0.0-preview.63",
+        "contentHash": "M2qEbjY8Uh5jpgrqDD7vJf2YXk3CmGbTHkb/t6w4F/aNyetOYk0LyekdwUSF0kZ+gTNMH/y6CTHBbJfgtMbIeA=="
       },
       "nanoFramework.System.IO.Streams": {
         "type": "Direct",
diff --git a/Tests/SslStreamTests_WiFi/SslStreamTests_WiFi.nfproj b/Tests/SslStreamTests_WiFi/SslStreamTests_WiFi.nfproj
index b098f11..cb9323a 100644
--- a/Tests/SslStreamTests_WiFi/SslStreamTests_WiFi.nfproj
+++ b/Tests/SslStreamTests_WiFi/SslStreamTests_WiFi.nfproj
@@ -37,7 +37,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="mscorlib">
-      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.52\lib\netnano1.0\mscorlib.dll</HintPath>
+      <HintPath>..\..\packages\nanoFramework.CoreLibrary.2.0.0-preview.63\lib\netnano1.0\mscorlib.dll</HintPath>
     </Reference>
     <Reference Include="nanoFramework.Runtime.Events">
       <HintPath>..\..\packages\nanoFramework.Runtime.Events.2.0.0-preview.13\lib\netnano1.0\nanoFramework.Runtime.Events.dll</HintPath>
diff --git a/Tests/SslStreamTests_WiFi/packages.config b/Tests/SslStreamTests_WiFi/packages.config
index b371c48..a5aac84 100644
--- a/Tests/SslStreamTests_WiFi/packages.config
+++ b/Tests/SslStreamTests_WiFi/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" targetFramework="netnano1.0" />
+  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" targetFramework="netnano1.0" />
   <package id="nanoFramework.Runtime.Events" version="2.0.0-preview.13" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Device.Wifi" version="2.0.0-preview.36" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="2.0.0-preview.22" targetFramework="netnano1.0" />
diff --git a/Tests/SslStreamTests_WiFi/packages.lock.json b/Tests/SslStreamTests_WiFi/packages.lock.json
index bbb3265..0b753dc 100644
--- a/Tests/SslStreamTests_WiFi/packages.lock.json
+++ b/Tests/SslStreamTests_WiFi/packages.lock.json
@@ -4,9 +4,9 @@
     ".NETnanoFramework,Version=v1.0": {
       "nanoFramework.CoreLibrary": {
         "type": "Direct",
-        "requested": "[2.0.0-preview.52, 2.0.0-preview.52]",
-        "resolved": "2.0.0-preview.52",
-        "contentHash": "cV9JEhoc2OV/UL602i5xmEwQpnn/gzVMlDTAIAMRxCNwBKNYLO9U50OkJykpGnO2SULTsmvFqQWEGZiuANBZHw=="
+        "requested": "[2.0.0-preview.63, 2.0.0-preview.63]",
+        "resolved": "2.0.0-preview.63",
+        "contentHash": "M2qEbjY8Uh5jpgrqDD7vJf2YXk3CmGbTHkb/t6w4F/aNyetOYk0LyekdwUSF0kZ+gTNMH/y6CTHBbJfgtMbIeA=="
       },
       "nanoFramework.Runtime.Events": {
         "type": "Direct",
diff --git a/nanoFramework.System.Net.nuspec b/nanoFramework.System.Net.nuspec
index 8fd07bc..cd37ef0 100644
--- a/nanoFramework.System.Net.nuspec
+++ b/nanoFramework.System.Net.nuspec
@@ -16,11 +16,11 @@
     <repository type="git" url="https://github.com/nanoframework/System.Net" commit="$commit$" />
     <copyright>Copyright (c) .NET Foundation and Contributors</copyright>
     <description>This package includes the nanoFramework System.Net assembly for .NET nanoFramework C# projects.
-This package requires a target with System.Net v$nativeVersion$ (checksum $checksum$).</description>
-    <tags>nanoFramework C# csharp netmf netnf networking</tags>
+This package requires a target with System.Net native contract hash $nativeContractHash$.</description>
+    <tags>nanoFramework C# csharp netmf netnf networking nfnc-$nativeContractHash$</tags>
     <dependencies>
       <group targetFramework=".NETnanoFramework1.0">
-        <dependency id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" />
+        <dependency id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" />
         <dependency id="nanoFramework.Runtime.Events" version="2.0.0-preview.13" />
         <dependency id="nanoFramework.System.Text" version="2.0.0-preview.23" />
         <dependency id="nanoFramework.System.Threading" version="2.0.0-preview.14" />
diff --git a/nanoFramework.System.Net/Properties/AssemblyInfo.cs b/nanoFramework.System.Net/Properties/AssemblyInfo.cs
index af89678..13b37d0 100644
--- a/nanoFramework.System.Net/Properties/AssemblyInfo.cs
+++ b/nanoFramework.System.Net/Properties/AssemblyInfo.cs
@@ -14,11 +14,6 @@
 [assembly: AssemblyProduct("System.Net")]
 [assembly: AssemblyCopyright("Copyright (c) .NET Foundation and Contributors")]
 
-////////////////////////////////////////////////////////////////
-// update this whenever the native assembly signature changes //
-[assembly: AssemblyNativeVersion("100.20.0.2")]
-////////////////////////////////////////////////////////////////
-
 // Setting ComVisible to false makes the types in this assembly not visible 
 // to COM components.  If you need to access a type in this assembly from 
 // COM, set the ComVisible attribute to true on that type.
diff --git a/nanoFramework.System.Net/System.Net.nfproj b/nanoFramework.System.Net/System.Net.nfproj
index dbe372c..e7a0f69 100644
--- a/nanoFramework.System.Net/System.Net.nfproj
+++ b/nanoFramework.System.Net/System.Net.nfproj
@@ -91,7 +91,7 @@
   </ItemGroup>
   <ItemGroup>
     <Reference Include="mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
-      <HintPath>..\packages\nanoFramework.CoreLibrary.2.0.0-preview.52\lib\netnano1.0\mscorlib.dll</HintPath>
+      <HintPath>..\packages\nanoFramework.CoreLibrary.2.0.0-preview.63\lib\netnano1.0\mscorlib.dll</HintPath>
     </Reference>
     <Reference Include="nanoFramework.Runtime.Events, Version=2.0.0.0, Culture=neutral, PublicKeyToken=c07d481e9758c731">
       <HintPath>..\packages\nanoFramework.Runtime.Events.2.0.0-preview.13\lib\netnano1.0\nanoFramework.Runtime.Events.dll</HintPath>
diff --git a/nanoFramework.System.Net/packages.config b/nanoFramework.System.Net/packages.config
index 487101b..d3d58ee 100644
--- a/nanoFramework.System.Net/packages.config
+++ b/nanoFramework.System.Net/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.52" targetFramework="netnano1.0" />
+  <package id="nanoFramework.CoreLibrary" version="2.0.0-preview.63" targetFramework="netnano1.0" />
   <package id="nanoFramework.Runtime.Events" version="2.0.0-preview.13" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.IO.Streams" version="2.0.0-preview.22" targetFramework="netnano1.0" />
   <package id="nanoFramework.System.Text" version="2.0.0-preview.23" targetFramework="netnano1.0" />
diff --git a/nanoFramework.System.Net/packages.lock.json b/nanoFramework.System.Net/packages.lock.json
index f278bd5..7a7dba2 100644
--- a/nanoFramework.System.Net/packages.lock.json
+++ b/nanoFramework.System.Net/packages.lock.json
@@ -4,9 +4,9 @@
     ".NETnanoFramework,Version=v1.0": {
       "nanoFramework.CoreLibrary": {
         "type": "Direct",
-        "requested": "[2.0.0-preview.52, 2.0.0-preview.52]",
-        "resolved": "2.0.0-preview.52",
-        "contentHash": "cV9JEhoc2OV/UL602i5xmEwQpnn/gzVMlDTAIAMRxCNwBKNYLO9U50OkJykpGnO2SULTsmvFqQWEGZiuANBZHw=="
+        "requested": "[2.0.0-preview.63, 2.0.0-preview.63]",
+        "resolved": "2.0.0-preview.63",
+        "contentHash": "M2qEbjY8Uh5jpgrqDD7vJf2YXk3CmGbTHkb/t6w4F/aNyetOYk0LyekdwUSF0kZ+gTNMH/y6CTHBbJfgtMbIeA=="
       },
       "nanoFramework.Runtime.Events": {
         "type": "Direct",