Problems validating manifest.xml

Prerequisites

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YOU MAY DELETE THE PREREQUISITES SECTION.

• I am running the latest version of Node and the tools
• I checked the documentation and found no answer
• I checked to make sure that this issue has not already been filed

Expected behavior

If I run:

npx office-addin-manifest validate manifest.xml

I receive:

Error: Unable to contact the manifest validation service.
FetchError: request to https://validationgateway.omex.office.net/package/api/check?clientId=devx failed, reason: self-signed certificate in certificate chain

Current behavior

I would like to see if the current manifest.xml file is valid

Steps to Reproduce

Open a terminal print this command:

npx office-addin-manifest validate manifest.xml

Context

• Operating System: mac 26.2 (25C56)
• Node version: v24.12.0
• Office version: 16.104.1 (26010228)
• Tool version: office-addin-manifest version ^2.1.2

Failure Logs

If i run the command add extra logs:

npx office-addin-manifest validate manifest.xml --ddd

These are the logs

npm info using npm@11.6.2
npm info using node@v24.12.0
npm verbose title npm exec office-addin-manifest validate manifest.xml --ddd
npm verbose argv "exec" "--" "office-addin-manifest" "validate" "manifest.xml" "--ddd"
npm verbose logfile logs-max:10 dir:/Users/my.username/.npm/_logs/2026-01-13T05_21_53_000Z-
npm verbose logfile /Users/my.username/.npm/_logs/2026-01-13T05_21_53_000Z-debug-0.log
error: unknown option '--ddd'
npm verbose cwd /Users/my.username/Work/addin/addin_ui
npm verbose os Darwin 25.2.0
npm verbose node v24.12.0
npm verbose npm  v11.6.2
npm verbose exit 1
npm verbose code 1

Start by reproducing npx office-addin-manifest validate manifest.xml with the reported Node and tool versions, then trace the office-addin-manifest validate entry point and its request to the manifest validation service. Done means a valid manifest can be checked without the reported certificate-chain failure, or the command returns a clear actionable error.