diff --git a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/Internal/CloneCollection.cs b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/Internal/CloneCollection.cs
index c418aad..69648d5 100644
--- a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/Internal/CloneCollection.cs
+++ b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/Internal/CloneCollection.cs
@@ -82,7 +82,7 @@ namespace ObservableCollections.Internal
             if (array != null)
             {
                 ArrayPool<T>.Shared.Return(array, RuntimeHelpersEx.IsReferenceOrContainsReferences<T>());
-                array = null!;
+                array = null;
             }
         }
 
diff --git a/src/ObservableCollections/ObservableCollections.csproj b/src/ObservableCollections/ObservableCollections.csproj
index e357766..1905873 100644
--- a/src/ObservableCollections/ObservableCollections.csproj
+++ b/src/ObservableCollections/ObservableCollections.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;netstandard2.1;net5.0;net6.0</TargetFrameworks>
@@ -18,8 +18,8 @@
             <CopySource Include="$(MSBuildProjectDirectory)\**\*.cs" Exclude="**\bin\**\*.*;**\obj\**\*.*;_InternalVisibleTo.cs" />
         </ItemGroup>
 
-        <Copy SourceFiles="@(CopySource)" DestinationFiles="$(DestinationRoot)\%(RecursiveDir)%(Filename)%(Extension)" SkipUnchangedFiles="true" UseHardlinksIfPossible="true" />
-
+        <Copy SourceFiles="@(CopySource)" DestinationFiles="$(DestinationRoot)\%(RecursiveDir)%(Filename)%(Extension)" SkipUnchangedFiles="true" UseHardlinksIfPossible="false" />
+        
         <!-- After copy, replace for unity codes -->
         <Exec Command="dotnet run -c $(ConfigurationName) --project $(MSBuildProjectDirectory)\..\..\tools\PostBuildUtility\PostBuildUtility.csproj -- replace-to-unity $(DestinationRoot)" />
     </Target>
diff --git a/tools/PostBuildUtility/Program.cs b/tools/PostBuildUtility/Program.cs
index 0f9afd1..0363fda 100644
--- a/tools/PostBuildUtility/Program.cs
+++ b/tools/PostBuildUtility/Program.cs
@@ -52,6 +52,7 @@ namespace PostBuildUtility
 
                 if (text != original)
                 {
+                    Console.WriteLine("Replace Output:" + path);
                     File.WriteAllText(path, text, noBomUtf8);
                 }
             }