"Manifest file not valid" error when deploying Outlook SSO add-in with production URLs #1020
Description
Hello,
I am implementing a custom Outlook add-in with SSO, using the same manifest.xml schema recommended in the official documentation and in examples such as this repository.
Context:
In the local environment (localhost), the manifest works correctly and allows me to deploy the add-in through the Microsoft 365 admin center without errors. Also, when deploying via sideloading, I can quickly verify that my add-in works as expected and successfully authenticates with SSO, using WebApplicationInfo in the manifest.xml.
However, when I update the URLs in the manifest.xml to point to my production environment, which uses Azure services (Azure Function, Storage Account - Static Web App), I get the error in the last stage of deployment via Microsoft 365 admin center:
In the production environment, the add-in itself works fine, but when I implement SSO, I encounter these issues.
Additionally, I can no longer perform sideloading tests after making this URL change.
What I have done:
- I have followed the step-by-step instructions from both the official Microsoft documentation and the sample repository.
- I have correctly updated the client ID and URL values in
<WebApplicationInfo>. - The app is registered in Azure AD (Entra ID) and the URLs match in both the registration and the manifest.
- The manifest.xml file validates successfully in the Office Add-in Validator.
My question:
What additional considerations should I take into account when updating the manifest and moving from local to production?