How to Resolve NamespaceMissing:Microsoft.Policies.Windows Error in Intune

Have you ever encountered an error while attempting to upload custom ADMX files in Intune? If you're facing the "ADMX file referenced not found NamespaceMissing:Microsoft.Policies.Windows" error, I can relate. In this article, I'll share my experience and guide you through the steps I took to resolve this issue and successfully upload custom ADMX files in Microsoft Intune.

Table of Contents

• Understanding the Error
• Solution: Uploading Windows ADMX Files
  • How to Obtained Windows ADMX Files
  • Uploading Windows ADMX Files to Intune
  • Validate the Solution

Understanding the Error

Before we jump into the solution, let's first understand the error message: "ADMX file referenced not found NamespaceMissing:Microsoft.Policies.Windows." This error indicates that the required Windows ADMX files are either missing or improperly configured in your Intune setup.

In this Example I try to Upload the Coogle Chrome ADMX files.
More about them and why I did that you can read here: Google Chrome Single Sign On (SSO) | Azure AD | scloud

Solution: Uploading Windows ADMX Files

The solution to this problem lies in ensuring the necessary Windows ADMX files are present in your Intune configuration.

Luckily, there is an easy fix for that. We just need to upload the current "Windows.admx" and "Windows.adml" file before uploading our custom ADMX file.

How to Obtained Windows ADMX Files

To obtain the required Windows ADMX files, follow these steps:

1. On an up-to-date Windows 10/11 system, navigate to this path: C:\Windows\PolicyDefinitions
2. Copy the "Windows.admx" file from this directory.
3. Additionally, copy the "Windows.adml" file from the "en-US" subfolder within the "PolicyDefinitions" directory.

If you don't have access to a Windows system, you can download those two files from my GitHub:

Uploading Windows ADMX Files to Intune

Once you have those two files, just upload them in Intune:

1. Open Intune
2. Navigate to "Devices > Windows> Configuration profiles > Import ADMX"
3. Press "+ Import"
4. Upload those two files

After that you can import your custom ADMX again, which should work now. 🎉

Validate the Solution

Here again with our example: Togeter with the Windows ADMX the Error "NamespaceMissing:Microsoft.Policies.Windows" does not appear again and the import was successful.