Microsoft Add-In manifest doesn't work on outlook web
I have developed a microsoft office add-in for outlook that can be seen here https://cdnqa.mcfile.com/mcoffice/manifest.outlook.xml
I have tested and it works as expected on local and production environment. I have validated the XMLs with the tool office-addin-manifest validate
That yields a positive result for multiple platforms, including web:
Based on the requirements specified in your manifest, your add-in can run on the following platforms; your add-in will be tested on these platforms when you submit it to the Office Store:
- Outlook 2013 or later on Windows
- Outlook 2016 or later on Windows
- Outlook 2019 or later on Windows
- Outlook 2013 or later on Mac
- Outlook 2016 or later on Mac
- Outlook 2019 or later on Mac
- Outlook on the web
- Outlook on Windows (Microsoft 365)
- Outlook on Mac (Microsoft 365)
Important: This analysis is based on the requirements specified in your manifest and does not account for any runtime JavaScript calls within your add-in. For information
about which API sets and features are supported on each platform, see Office Add-in host and platform availability. (https://docs.microsoft.com/office/dev/add-ins/overview/office-add-in-availability).
*This does not include mobile apps. You can opt-in to support mobile apps when you submit your add-in.
The manifest is valid.
But when trying to open the taskpane on outlook web I'm faced with the following error:
Note that this error do not exists on the desktop version. I can use the app normally on all other versions except web and web based like the new outlook desktop. Do anyone had a similar issue and know the cause or how to troubleshoot web add-ins?
As suggested by Eugene, importing office.js and implementing an office.initialize call enabled the app to load.