Power Platform Community Forum Thread Details

My error occurs, when i try to save a Custom Prompt which has a Document Output, meaning that it fills a Word Template and hands a link back to the agent.

I know this feature is still in preview, but it works perfectly until I want to save it. The error message is: "An error occurred while saving the custom prompt. Please try again later."

When I test my Custom Prompt, it works fine and the document it creates is filled successfully with the specified values.

I currently run Copilot Studio without a Power Automate Premium license, but this feature is not marked with a Premium diamond, so I assume it should work.

Does anyone have an idea why I cannot save the Custom Prompt? Does the feature work with a Power Automate Premium license?

Categories:

General topics

,Hello SK-09040723-0

This is currently a known preview limitation with Custom Prompts using Document Output in Copilot Studio and is not caused by incorrect configuration or missing field mappings. In your case, the Word template is uploaded correctly, fields are identified, and the document is successfully generated during testing, which confirms that runtime execution works as expected under your interactive user context. However, when saving the Custom Prompt, Copilot Studio attempts to provision a hidden background orchestration layer (similar to a managed flow and connection reference) required for agent runtime execution, and this step fails in environments that do not have a Power Automate Premium license assigned.
Although the feature is not marked with a Premium connector in the UI, the save operation internally depends on capabilities backed by SharePoint, Word Online (Business), and Dataverse integrations that require service‑level provisioning rights. As a result, testing succeeds but saving fails with the generic error message. Assigning a Power Automate Premium license to the maker currently allows the Custom Prompt to be saved successfully and the document output to function during actual agent runtime as well.
Reference Document(

Prerelease documentation and is subject to change)

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Document output (preview) - Microsoft Copilot Studio | Microsoft Learn