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How to Sideload Office Web Add-In Manifests in Production Mode

Partner Editor Sep 27, 2026 869 views

Question details

Needs a method to deploy an Office.js add-in manifest in a closed network using volume-licensed Office 2019 or 2021 without relying on the Office Store, Microsoft 365, SharePoint, or manual trusted folders.

Sideloading Office Web Add-In Manifests in Production Mode

Product: Microsoft Office 2019 and 2021
Device & OS: not provided
Scenario: Deploying custom Office Web Add-ins in a strictly controlled enterprise closed-network environment.
Observed behavior: Standard deployment methods are unavailable due to network restrictions and infrastructure limitations, requiring specialized production sideloading strategies.

Before you start

Compile your network security policies, exact Office volume-license versions, MSI deployment plans, and required automatic loading behaviors before consulting developer support.

Solution 1Recommended

Consult Microsoft Q&A for Specialized Deployment Guidance

Because this involves complex closed-network deployment and volume-licensed Office versions, you should seek guidance from the specialized Office Development community.

Sideloading Office Web Add-in manifests without Microsoft 365 centralized deployment, SharePoint, or manual trusted folders requires highly specific network configurations. The Microsoft Q&A Office Development channel is the official platform for resolving these enterprise infrastructure challenges.

Navigate to Microsoft Q&A

Open your web browser and go to the Microsoft Q&A website. Navigate to the 'Office Development' section using the relevant tags.

Provide Infrastructure Details

Create a new post detailing your exact network restrictions, the volume-licensed versions in use (Office 2019/2021), your proposed manifest hosting method, and your MSI deployment plan.

Engage with IT Professionals

Monitor your post for responses from enterprise deployment experts who can provide scripts or Group Policy workarounds tailored to your closed network.

Consult Microsoft Q&A for Specialized Deployment Guidance

Community Feedback: Once you receive a working solution on Microsoft Q&A, remember to use the feedback tool to upvote the answer so other administrators in closed networks can benefit.

Solution 2

Deploy via Centralized Network Share and Group Policy

Use a secure network share paired with Windows Group Policy to designate a trusted add-in catalog across your organization.

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Simplify Document Processing with WPS Office

If managing complex add-in deployments, manifest sideloading, and network restrictions in Microsoft Office becomes overwhelming, consider deploying WPS Office. It provides a lightweight, highly compatible alternative for document processing that requires minimal enterprise configuration.

1. Download the Installer: Access the official WPS Office website to download the free standalone installer suitable for your network environment.
2. Deploy Across Endpoints: Use your standard deployment tools to distribute WPS Office to user machines quickly and efficiently.
3. Open and Edit Files: Launch WPS Office to immediately open existing Microsoft Office documents without needing specialized third-party add-ins for core features.

Seamlessly compatible with Microsoft Word, Excel, and PowerPoint formats.Lightweight installation package ideal for restricted and closed networks.Requires minimal centralized deployment overhead compared to complex add-in manifests.Familiar tabbed user interface ensures zero learning curve for employees.

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Frequently Asked Questions

Can I sideload Office Web Add-ins without an internet connection?

Yes, in closed networks, you can host the add-in files and manifest on an internal web server or secure network share. You must then configure client machines to trust this internal location via Group Policy.

Does Office 2019 support the same add-in features as Microsoft 365?

No. Office 2019 supports older requirement sets and Office.js APIs compared to the constantly updated Microsoft 365. You must verify that your add-in manifest only requires APIs supported by the Office 2019 build.

Why avoid manual trusted folders for add-ins in production?

Manually configuring trusted folders on individual endpoints is not scalable for enterprise environments. It makes updates difficult to manage and can introduce security inconsistencies, which is why centralized deployment or GPO is strictly preferred.

What is an MSI deployment plan for add-ins?

An MSI deployment plan involves packaging the necessary registry keys or local files into a Windows Installer (.msi) package, which can then be pushed silently to all computers in a closed network using tools like Microsoft Endpoint Configuration Manager.

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