AddContentType verb in sitescript fails silently

[fannazephyr]

Target SharePoint environment

SharePoint Online

What SharePoint development model, framework, SDK or API is this about?

Site designs & site scripts

Developer environment

Windows

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

-NA

Describe the bug / error

I'm using the addContentType verb inside the subactions of a createSPList action in a SharePoint site script to add a custom content type to a newly created document library. The content type already exists in the site collection. Here's the structure:

json
{
"verb": "createSPList",
"listName": "ProjectDocs",
"templateType": 101,
"subactions": [
{
"verb": "addContentType",
"name": "Project Document"
}
]
}
The list is created successfully, but the content type is not added. There are no errors, and the action fails silently. I suspect this is due to a timing issue, where the list is not fully provisioned or content types are not yet enabled when the addContentType action runs.

Steps to reproduce

1.Create a site script like above to create a new library and add content types to it
2.Register the site design with a hub site.
3.Associate another site with hub and the site template is applied.
4. The library is created but content type is not added in the library.

Expected behavior

The content type should be added to the list as part of the site script execution.

[Ashlesha-MSFT]

Hello @fannazephyr,
Thank you for bringing this issue to our attention. We will look into it and get back to you shortly.

[Ashlesha-MSFT]

@fannazephyr,
The site script engine has known constraints—especially around verbs like addContentType. These limitations mainly involve supported verbs, action ordering, and provisioning timing.

There’s increasing evidence this is a timing or sequencing issue, rather than a defect in the action itself.

[fannazephyr]

Thanks Ashlesha, Is there a solution to this how addContentType verb be correctly be used. This basically makes the verb unusable due to timings and sequencing issues

[Ashlesha-MSFT]

@fannazephyr,
We were able to reproduce the issue you reported with the addContentType verb failing silently inside the createSPList action in site scripts.
The list is created, but content types are often not yet fully provisioned or enabled when addContentType runs.
The verb works reliably only when adding default content types or content types created earlier within the same script.

As We were able to reproduce the issue, and we are investigating it. We have logged this as a bug, and our engineering team will look into it.

[fannazephyr]

Thanks for the update. Yes that is correct.
I will wait for the update for the bug.