We upgraded a service from ASP.NET 8 to 10. No application code changed—but our Puppeteer-based document pipeline completely broke.

The root cause wasn’t .NET. It was a subtle base image change:

Debian → Ubuntu , which replaced a working Chromium install with a non-functional Snap wrapper inside Docker.

The Setup

Our document generation pipeline works like this:

Render HTML using Puppeteer

Use Chromium as the headless browser

Post-process assets with Sharp

Run everything inside a Docker container

This setup worked reliably on ASP.NET 8.

What Changed?

As part of the upgrade:

From: mcr.microsoft.com/dotnet/aspnet:8.0 (Debian-based)

To: mcr.microsoft.com/dotnet/aspnet:10.0 (Ubuntu-based)

At first glance, nothing looked risky.…