UmbracoCMS 401 Error: Troubleshooting Failed Resource Loading

by Felix Dubois 62 views

Introduction

Hey guys! We've got a situation where UmbracoCMS is throwing a 401 error when trying to load resources, and it seems to be tied to the .NET 10 preview SDK. This article dives deep into the issue, the steps to reproduce it, and the environments where it's happening. We'll break down the bug, explore the expected behavior, and provide a detailed guide for reproducing and debugging the problem. So, let's get started and figure out what's going on!

The Bug: 401 Error with UmbracoCMS

So, the main issue we're tackling is that UmbracoCMS is failing to load pages, and the browser is reporting a 401 error. This usually means there's an authentication problem, but in this case, it seems to be linked to a specific .NET SDK preview version. When running UmbracoCMS with dotnet-sdk-10.0.100-preview.7.25380.108, the application throws a "Failed to load resource: the server responded with a status of 401()" error. This issue prevents the login page from loading correctly, making it impossible to access the CMS.

Key Details:

  • Application: UmbracoCMS
  • Operating System: Windows 11 24H2
  • CPU: X64
  • .NET Build Number: dotnet-sdk-10.0.100-preview.7.25380.108
  • Github Link: Umbraco-CMS

The problem occurs specifically with the dotnet-sdk-10.0.100-preview.7.25380.108 build. Previous versions like dotnet-sdk-9.0.303 and dotnet-sdk-10.0.100-preview.7.25374.104 work just fine. This narrows down the issue to a potential regression in the newer preview build.

Expected Behavior

Ideally, the login page should load without any hiccups. You know, smooth sailing! Users should be able to access the UmbracoCMS login page and proceed to log in without encountering any 401 errors. This is the basic expectation for any web application, and when it fails, it's a major roadblock.

Steps to Reproduce

Alright, let's dive into the nitty-gritty of how to reproduce this bug. Follow these steps, and you'll be able to see the issue firsthand.

App Repro Steps

  1. Prerequisites: Make sure you've got dotnet-sdk-10.0.100-preview.7.25380.108 installed on your machine.

  2. Copy the Application: Grab the Umbraco-CMS files from the specified location (\\...\2541067\Umbraco-CMS) and copy them to your local machine. (Since this is a private path, you'll need to use the appropriate internal network location).

  3. Update runtimeconfig.json: Modify the Umbraco.Web.UI.runtimeconfig.json file to use the problematic .NET runtime version. Here’s the snippet you need to update:

    "frameworks": [
      {
        "name": "Microsoft.NETCore.App",
        "version": "10.0.0-preview.7.25380.108"
      },
      {
        "name": "Microsoft.AspNetCore.App",
        "version": "10.0.0-preview.7.25380.108"
      }
    ],

  4. Launch the Application: Run Umbraco.Web.UI.exe.

  5. Open Umbraco: Click the "Open Umbraco" button, and you should see the 401 error in your browser's developer tools.

App Debug Steps

For a more in-depth look, you can debug the application. Here’s how:

  1. Prerequisites: Ensure dotnet-sdk-10.0.100-preview.7.25372.102 (or a similar working version) is installed.

  2. Get the Source Code: Copy the Umbraco-CMS source code from \\...\2541067\AppSourceCode\Umbraco-CMS-contrib.zip, extract it to your local machine, or clone it from Umbraco-CMS GitHub repository.

  3. Adjust Build Settings:

    • In \Umbraco-CMS-contrib\Umbraco-CMS-contrib\Directory.Build.props, change <TreatWarningsAsErrors> to false.
    • Update the global.json file to use the .NET version installed on your machine.

  4. Initialize Git: Navigate to the \Umbraco-CMS-contrib\Umbraco-CMS-contrib folder and run these Git commands:

    git init
git add .
git commit -m "initial"

  5. Open in Visual Studio: Open umbraco.sln with Visual Studio.

  6. Build the Project: Build the \Umbraco-CMS-contrib\Umbraco-CMS-contrib\src\Umbraco.Web.UI\Umbraco.Web.UI.csproj project.

  7. Update runtimeconfig.json (Again): Modify \Umbraco-CMS-contrib\Umbraco-CMS-contrib\src\Umbraco.Web.UI\bin\Debug\net9.0\Umbraco.Web.UI.runtimeconfig.json to use the problematic runtime version:

    "frameworks": [
      {
        "name": "Microsoft.NETCore.App",
        "version": "10.0.0-preview.7.25380.108"
      },
      {
        "name": "Microsoft.AspNetCore.App",
        "version": "10.0.0-preview.7.25380.108"
      }
    ],

  8. Set Launch Profile: Switch to launching the application with Umbraco.Web.UI from Visual Studio.

  9. Run the Project: Press F5 to run the Umbraco.Web.UI project.

  10. First-Time Setup (If Applicable): If this is your first time running the application, follow these steps:

    • Fill in your Name, Email, and Password.
    • Click "Next" twice.
    • Click "Install."

  11. Open Umbraco (Again): If it's not the first time, just click the "Open Umbraco" button.

Following these steps should reproduce the 401 error, allowing you to debug and investigate further.

Exceptions and Errors

When the bug hits, you'll see the dreaded