Build error “An attempt was made to load an assembly with an incorrect format ” after upgrade net framework 4.5.2 to 4.7.1

Question

We are trying to update the framework of our program. We currently have it in version 4.5.2 and we want to update it to version 4.7.1

We have changed all the csproj

Answer 1

UPDATE: As Josh suggests below, now that 4.7.2 is available, upgrade to that .NET version for the best resolution of this problem.

If stuck with 4.7.1: This probably isn't addressing the root of the problem, but if you want to get over this for the moment, then find the offending project and edit its settings (rclick project, 'Properties', then 'Build' tab.)

Set 'Generate serialization assemblies' to 'Off' for Release mode.

If it still complains, try adding the following <Target>s to your .csproj file (e.g. towards the bottom, just inside the enclosing </Project> root tag:

<Target Name="RemoveDesignTimeFacadesBeforeSGen" BeforeTargets="GenerateSerializationAssemblies">
    <ItemGroup>
      <ReferencePath Remove="@(_DesignTimeFacadeAssemblies_Names->'%(OriginalIdentity)')" />
    </ItemGroup>
    <Message Importance="normal" Text="Removing DesignTimeFacades from ReferencePath before running SGen." />
  </Target>
  <Target Name="ReAddDesignTimeFacadesBeforeSGen" AfterTargets="GenerateSerializationAssemblies">
    <ItemGroup>
      <ReferencePath Include="@(_DesignTimeFacadeAssemblies_Names->'%(OriginalIdentity)')" />
    </ItemGroup>
    <Message Importance="normal" Text="Adding back DesignTimeFacades from ReferencePath now that SGen has run." />
  </Target>

Answer 2

This issue is fixed in the latest .net dev pack 4.7.2:

https://github.com/dotnet/sdk/issues/1630#issuecomment-415811457

https://www.microsoft.com/net/download/thank-you/net472-developer-pack

Answer 3

The root of the issue is that the assembly you are seeing in the error message has an incorrect entry in the .NET Framework unification table.

That incorrect entry causes the assembly reference to not correctly unify with the assembly in the framework and leads to that error. This is documented as a known issue in .NET Framework 4.7.1.

As a workaround you can add these targets to your project. They will remove the DesignFacadesToFilter from the list of references passed to SGEN (and add them back once SGEN is done)

    <Target Name="RemoveDesignTimeFacadesBeforeSGen" BeforeTargets="GenerateSerializationAssemblies">
      <ItemGroup>
        <DesignFacadesToFilter Include="System.IO.Compression.ZipFile" />
        <_FilterOutFromReferencePath Include="@(_DesignTimeFacadeAssemblies_Names->'%(OriginalIdentity)')" 
            Condition="'@(DesignFacadesToFilter)' == '@(_DesignTimeFacadeAssemblies_Names)' and '%(Identity)' != ''" /> 
        <ReferencePath Remove="@(_FilterOutFromReferencePath)" />
      </ItemGroup>
      <Message Importance="normal" Text="Removing DesignTimeFacades from ReferencePath before running SGen." /> </Target>

    <Target Name="ReAddDesignTimeFacadesBeforeSGen" AfterTargets="GenerateSerializationAssemblies">
      <ItemGroup>
        <ReferencePath Include="@(_FilterOutFromReferencePath)" />
      </ItemGroup>
      <Message Importance="normal" Text="Adding back DesignTimeFacades from ReferencePath now that SGen has ran." />
    </Target>

Edit: If the above doesn't work, please share a detailed msbuild log to help understand why the target doesn't work.

Another option (machine wide) is to add the following binding redirect to sgen.exe.config:

    <runtime>
      <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <dependentAssembly>
          <assemblyIdentity name="System.IO.Compression.ZipFile" publicKeyToken="b77a5c561934e089" culture="neutral" />
          <bindingRedirect oldVersion="0.0.0.0-4.2.0.0" newVersion="4.0.0.0" />
        </dependentAssembly>
      </assemblyBinding>
    </runtime>

This will only work on machines with .NET Framework 4.7.1. installed. Once .NET Framework 4.7.2 is installed on that machine, this workaround should be removed.