AuthentificationNotConfigured (Copilot agent)

Edit: This may not be the cause. I've provided an updated solution in my recent comment.

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The known issue and workaround is logged here: https://admin.powerplatform.microsoft.com/knownissues/4571133

Problem

Microsoft Copilot Studio is rolling out full Data Loss Prevention (DLP) enforcement for all tenants and deprecating secondary DLP controls via Power Shell cmdlets.
That will cause DLP errors to show for all agents in Copilot Studio.

Workaround

First stage (January -February 2025) will enforce SoftEnabled DLP mode for all agents 
Second stage (February-March 2025) will enforce Enabled mode for all agents and power shell cmdlets will be deprecated

Agent authors need to work with tenant admin to ensure agent configuration is aligned with Data Loss Prevention policies enforced for the environment.
Based on the error, either

- tenant admin can adjust DLP policy to remove violation

- or agent author can update Agent configuration (or remove connector usage) to resolve DLP violation.

here is link to documentation for DLP configuraito in Copilot Studio:
Configure data loss prevention policies for agents - Microsoft Copilot Studio | Microsoft Learn