MSBuild targets must use unique names.

ILSpy/ILSpy.csproj

@@ -398,7 +398,7 @@
   Copy them to a local folder and then include them as Content-items in the AddIn.
   (related to https://github.com/icsharpcode/ILSpy/issues/511)
   -->
-  <Target Name="PostBuild" AfterTargets="PostBuildEvent">
+  <Target Name="CopyNugetPackagesToAddIn" AfterTargets="PostBuildEvent">
     <ItemGroup>
       <NuGetPackagesToCopy Include="$(TargetDir)System.ValueTuple.dll" />
       <NuGetPackagesToCopy Include="$(TargetDir)System.Collections.Immutable.dll" />
@@ -425,7 +425,7 @@
 
   <Import Project="$(VCToolsVersionPropsFile)" Condition="Exists('$(VCToolsVersionPropsFile)')" />
   
-  <Target Name="PostBuild" AfterTargets="PostBuildEvent">
+  <Target Name="ApplyStackExtension" AfterTargets="PostBuildEvent">
     <Exec Condition="'$(VCToolsVersion)'!=''" Command="&quot;$(VCBasePath)Tools\MSVC\$(VCToolsVersion)\bin\Hostx64\x64\editbin.exe&quot; /stack:16777216 &quot;$(TargetPath)&quot;&#xD;&#xA;EXIT 0" />
   </Target>
 </Project>