Outlook getCallbackTokenAsync fails when selecting multiple items (Office on the web)

[manuelsidler]

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: Office on the web
• Host [Excel, Word, PowerPoint, etc.]: Outlook
• Office version number: Office 365
• Operating System: macOS Sonoma 14.2
• Browser (if using Office on the web): Edge for Mac (Version 120.0.2210.61 (Official build) (arm64))

Expected behavior

When selecting multiple items and calling Office.context.mailbox.getCallbackTokenAsync, it should return the access token.

Current behavior

When running the add-in on Outlook on the web, selecting multiple items and calling Office.context.mailbox.getCallbackTokenAsync throws an error:

Steps to reproduce

1. Clone the example GH repo to reproduce the issue (see link below)
2. Run the add-in with npm install and npm run dev-server
3. Side load the add-in on Outlook on the web
4. Select multiple items
5. Open the add-in
6. Click the Get access token button
7. Open the developer tools
8. The console contains the error (see screenshot above)

The same steps on Outlook for Mac work fine.

Link to live example(s)

• GitHub Repo with example to reproduce: https://github.com/manuelsidler/outlook-addin-multiselect

Context

We need the access token to set custom properties on the selected items via REST API.

[manuelsidler]

@exextoc the error seems to be fixed:

[exextoc]

@manuelsidler Thank you for confirming. Closing the issue.