Sideload the manifest (Windows / Mac)

In some organizations, AppSource is restricted by IT policy. In that case, you can install the Relm Pro Excel add-in by sideloading the manifest XML directly. This page covers the mechanics on Windows and Mac.

Recommended path: Install from AppSource is simpler and handles updates automatically. Only sideload when AppSource isn't an option.

Get the manifest

Download from relm.ai/excel-plugin. Save the file (manifest.prod.xml or similar). The manifest is a public, signed XML file — sharing it doesn't grant anyone access to your data.

Sideload on Windows

1. Open Excel.
2. File → Options → Trust Center → Trust Center Settings → Trusted Add-in Catalogs.
3. Add a network share path or local folder where you've placed the manifest.
4. Tick Show in Menu, then click OK.
5. Restart Excel.
6. Insert → My Add-ins → Shared Folder — pick Relm Pro.

Microsoft's full guide is at learn.microsoft.com/en-us/office/dev/add-ins/testing/create-a-network-shared-folder-catalog-for-task-pane-and-content-add-ins.

Sideload on Mac

1. Quit Excel.

2. Place the manifest file at:

   ~/Library/Containers/com.microsoft.Excel/Data/Documents/wef/
   

   You may need to create the wef folder if it doesn't exist.

3. Re-open Excel.

4. Insert → My Add-ins → Developer — pick Relm Pro.

Microsoft's full guide: learn.microsoft.com/en-us/office/dev/add-ins/testing/sideload-an-office-add-in-on-mac.

After sideload

The Relm Pro ribbon tab appears in Excel. Click Open Taskpane and sign in via the device-link flow.

Updates

Sideloaded manifests don't auto-update like AppSource. If we ship a manifest change (rare — usually only when adding a new ribbon button or icon), we'll announce it. To get the new version: re-download the manifest, replace the old one in the same location, restart Excel.

The actual JavaScript bundle is served from excel-plugin.relm.ai and updates independently of the manifest, so most updates ride out without action.

Excel for the web

Sideloading works on Excel Online too, via a different path:

• Insert → Office Add-ins → Upload My Add-in and select the manifest file.

This must be done per-tenant; once uploaded, every user in your tenant can install it without re-uploading.

Common issues

• "Manifest is not valid." The manifest version may be too old; re-download from relm.ai/excel-plugin.
• "Add-in does not load." The add-in's web content lives at excel-plugin.relm.ai; if your network blocks that, the taskpane won't render. Whitelist excel-plugin.relm.ai and relm.ai in your firewall.
• Mac, "An error occurred while opening the add-in." Sometimes a stale wef cache. Clear the wef folder, replace the manifest, restart Excel.

What's next

• Install from AppSource (the easier path)
• Sign in via device link
• Excel troubleshooting