Power Platform Community Forum Thread Details

Hello Community,

We are experiencing an issue with an agent built using the new Copilot Studio experience.

Until July 25, 2026, users were able to add documents and other context to the conversation through the "+" button in Microsoft 365 Copilot. Since then, the functionality appears to have stopped working without any intentional changes on our side.

Environment

Agent created using the new Copilot Studio UI
Published and accessible through Microsoft 365 Copilot
Issue reproducible for multiple users

Observations

The agent was created using the new Copilot Studio experience.
We cannot find any agent setting that enables or disables document uploads or context attachment.
The functionality worked correctly until July 25, 2026.
Starting around that date, the "+" button used to add context (documents, files, etc.) became unavailable/disabled in Microsoft 365 Copilot.
The "/" command that normally allows users to add context or reference content is also unavailable.
No configuration, security, or access changes were made to the agent.
The issue occurs in both Microsoft 365 Copilot Web and the Microsoft 365 Copilot app.
When using the same agent through Copilot in Teams or Copilot in Outlook, users can still attach documents successfully.

Question

Has anyone experienced similar behavior recently?

Is there:

A new setting or policy controlling document/context uploads for custom agents in Microsoft 365 Copilot?
A known service change that occurred around July 25, 2026?
Any troubleshooting steps we should investigate?

We would appreciate any guidance or insights.

Thank you!

Categories:

Copilot Studio skills development

General topics

We reviewed this against current Microsoft documentation and known channel behavior. At this time, this appears to be expected behavior in the Microsoft 365 Copilot channel for Copilot Studio agents, rather than a configurable agent setting.

What we validated:

In Copilot Studio channel documentation, Microsoft 365 Copilot has channel-specific limitations, including unsupported File message type behavior.
There is currently no agent-level toggle in the new Copilot Studio UX to enable or disable user document/context attachment for this channel.
Behavior can differ by host channel, so it is possible for attachment/context actions to work in Teams or Outlook while being unavailable in Microsoft 365 Copilot web/app.