Use ReadyToRun or Ahead-Of-Time (AOT) Compilation

Reason

According to Microsoft documentation, the SDK will precompile the assemblies that are distributed with the application. For self-contained applications, this set of assemblies will include the framework. It's important to note that C++/CLI binaries are not eligible for ReadyToRun compilation.

Solution

To exclude specific assemblies from ReadyToRun processing, use the <PublishReadyToRunExclude> list in your project file. For example, to exclude the IronPdf.dll assembly:

<ItemGroup>

    <PublishReadyToRunExclude Include="IronPdf.dll" />
</ItemGroup>

<ItemGroup>

    <PublishReadyToRunExclude Include="IronPdf.dll" />
</ItemGroup>

This XML snippet should be added to your project file (.csproj) to prevent the specified assemblies from being precompiled with ReadyToRun, thus avoiding potential licensing or tampering issues.

System.Environment.FailFast on First IronPDF Call

In some Windows deployments, IronPDF crashes the process immediately on the first IronPDF call with no application-level log output. Windows Event Log records an entry similar to:

The application requested process termination through System.Environment.FailFast.
Message: Stack: at System.Environment.FailFast(System.String)
  at <Module>..cctor()
  at Program.<Main>$(System.String[])

This is a different failure from the licensing exception above. The crash occurs during static initialization before normal logging is available, so no IronPDF log lines appear before the process terminates.

This pattern has been confirmed in ASP.NET Core applications hosted in IIS on Windows Server with PublishReadyToRun enabled. It has been reproduced on:

• IronPDF 2026.4.1
• .NET 10
• IIS (w3wp.exe) on Windows Server 2025 Datacenter
• AWS EC2 win-x64 publish target

<ItemGroup>
    <PublishReadyToRunExclude Include="IronPdf.dll" />
</ItemGroup>

<ItemGroup>
    <PublishReadyToRunExclude Include="IronPdf.dll" />
</ItemGroup>

<PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <PublishReadyToRun>true</PublishReadyToRun>
</PropertyGroup>

<ItemGroup>
    <PackageReference Include="IronPdf" Version="2026.4.1" />
</ItemGroup>

<ItemGroup>
    <PublishReadyToRunExclude Include="IronPdf.dll" />
</ItemGroup>

<PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <PublishReadyToRun>true</PublishReadyToRun>
</PropertyGroup>

<ItemGroup>
    <PackageReference Include="IronPdf" Version="2026.4.1" />
</ItemGroup>

<ItemGroup>
    <PublishReadyToRunExclude Include="IronPdf.dll" />
</ItemGroup>