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!