A useful validation step after importing custom ADMX settings is to export the resulting Intune profile and compare it with the vendor documentation. This confirms that the setting name, supported Windows version, and value format match the template you intended to use.
If a policy does not apply, review the device event logs and the MDM diagnostics report before changing the template. Most failures are caused by assignment scope, unsupported OS builds, or value formatting rather than the ADMX import itself.
Custom ADMX and ADML imports are helpful when a required Windows policy is not yet available as a native Intune setting. Treat every import like configuration source code: keep the original vendor files, document the version, and test the policy in a separate device group first.
After importing the templates, verify that the settings appear in the expected Intune category and that the generated policy writes the correct registry values on a test device. This avoids troubleshooting confusion later when multiple custom templates exist in the same tenant.
Most of the policies you’ll ever need are already exposed in Intune’s Settings Catalog — but every IT environment has at least one app whose admins still ship a custom ADMX/ADML template from the on-prem Group Policy days. Adobe Reader, FortiClient, custom in-house tools, and a long tail of vendor utilities all use this format, and Intune supports it natively as long as you know the slightly hidden import workflow. This post walks through importing a custom ADMX/ADML pair into Microsoft Intune end-to-end — where to grab the template files, how to upload them, how to assign the resulting profile, and what to expect on the client. Plus the debugging steps for the most common import failures.
With the Intune service release 2208 there is a really nice feature that provides the support to import ADMX and ADML templates very easy into Intune. This helps you create configurations for e.g. third-party products. I will explain how this works based on Firefox.
