[Public] IronPDF in AWS Lambda (.NET 8): Fixing Missing Chromium Binary Errors

Overview

When running IronPDF inside an AWS Lambda container image (typically on Linux) after upgrading to .NET 8 and using IronPDF, developers may encounter this error:

IronSoftware.Exceptions.IronSoftwareEmbeddedDeploymentMissingException:
Failed to find embedded resource 'Chrome.linux-x64.zip'

This occurs during the PDF rendering engine's startup, particularly when using ChromePdfRenderer.

Common Error Stack Trace

Unhandled exception. System.Exception: Error while convert DOCX document to HTML:
IronSoftware.Exceptions.IronSoftwareEmbeddedDeploymentMissingException: Failed to find embedded resource 'Chrome.linux-x64.zip'
   at IronSoftware.Deployment.AssetManager.GetEmbededResourceStream(...)
   at IronSoftware.Deployment.EmbeddedResourceDeployment.Deploy()
   at IronPdf.Engines.Chrome.LocalChromeClient.Initialize()

Why This Happens

This error is caused by one or more of the following issues:

1. Missing or Inaccessible Embedded Resources

IronPDF relies on embedded resources like Chrome.linux-x64.zip to extract and run a headless version of Chromium for rendering. If the runtime doesn't match the expected platform or IronPDF is unable to locate the embedded binary, it throws this exception.

2. Incorrect Execution Context

The app may appear to be running on Linux, but tools like AWS Lambda Mock Test Tool (when run locally) will execute the function on the host OS — commonly Windows — even if the Dockerfile targets Linux. This causes a mismatch between the expected embedded resource and the actual runtime.

3. Using `IronPDF.Slim` on the Wrong Platform

The IronPDF.Slim NuGet package is optimized for Linux-only scenarios. Using it on Windows or Windows-based Lambda runtimes will sometimes fail due to binaries for Windows platform is not downloaded at runtime. Use IronPDF package to run on Windows.

How to Fix the Issue

1. Ensure You're Running on the Correct Runtime

When using AWS Lambda with container images:

Verify that your Dockerfile targets Linux and your image is being run on AWS Lambda’s Linux environment.
Do not test using Mock Tools on Windows, as this will not mimic the correct environment.

2. Use the Full `IronPDF` Package If You Need Cross-Platform Support

If you're testing on both Windows and Linux, or locally on Windows:

Install-Package IronPdf

Instead of:

Install-Package IronPdf.Slim

IronPDF.Slim is recommended for Linux
IronPDF (non-slim) includes support for both Windows and Linux

3. Testing Locally? Use Docker to Simulate AWS Lambda Linux

When testing locally, use Docker to replicate the Lambda environment:

docker build -t my-lambda-test .
docker run --rm my-lambda-test

This ensures your function runs with Linux-specific dependencies and that IronPDF loads the correct embedded Chromium binary.

Dockerfile Essentials for IronPDF in AWS Lambda (Linux)

Ensure your container installs the required dependencies:

FROM public.ecr.aws/lambda/dotnet:8

# Install Linux packages required for Chromium
RUN yum install -y \
pango.x86_64 libXcomposite.x86_64 libXcursor.x86_64 libXdamage.x86_64 \
libXext.x86_64 libXi.x86_64 libXtst.x86_64 cups-libs.x86_64 \
libXScrnSaver.x86_64 libXrandr.x86_64 GConf2.x86_64 alsa-lib.x86_64 \
atk.x86_64 gtk3.x86_64 ipa-gothic-fonts \
xorg-x11-fonts-100dpi xorg-x11-fonts-75dpi \
xorg-x11-utils xorg-x11-fonts-cyrillic \
xorg-x11-fonts-Type1 xorg-x11-fonts-misc \
glibc-devel.x86_64 at-spi2-atk.x86_64 mesa-libgbm.x86_64

Then copy your published .NET app into the container and deploy as usual.