Copilot returning error "something went wrong"

Question

An account-specific Copilot data corruption bug triggered by creating/deleting an AI agent.

• Another Microsoft account works on the same devices.
• Issue started immediately after creating and deleting an AI agent.
• Responses stream completely, then disappear.
• Sidebar conversation history updates at the exact moment of failure.
• Console error: Virtualizer index less than zero, cannot render child rows.
• Stack trace includes unstable_scheduleCallback.

Answer 1

The described behavior isn’t covered in the provided documentation for Copilot or Copilot Studio error handling, and no documented fix exists in the context for an account‑specific “something went wrong” loop tied to creating/deleting an AI agent.

The closest relevant guidance in the context is:

• Generic “Something went wrong”/unexpected error messages are treated as backend or system errors where the recommended action is to retry later or escalate to support if the problem persists.
• In Copilot Studio and Dynamics 365 Sales Copilot scenarios, when Copilot fails in ways not resolved by configuration checks, the guidance is to open a support case and have it escalated.
• For persistent, tenant‑ or account‑specific Copilot issues in Microsoft 365 (including cases where other accounts work fine on the same devices), successful resolutions in practice have required Microsoft support intervention and escalation.

Given that:

1. Another Microsoft account works on the same devices, which strongly suggests an account‑ or backend‑profile issue rather than a local client problem.
2. The issue started immediately after creating and deleting an AI agent, which aligns with the pattern of backend configuration or data issues seen in other Copilot‑related products.
3. The error is reproducible and tied to this specific account, and not covered by the documented Copilot Studio error codes or generic “try again later” cases.

The actionable path supported by the context is:

1. Treat this as a backend/system error rather than a client bug.
2. Collect clear repro details (time, region, account type, exact steps, and the console error Virtualizer index less than zero, cannot render child rows).
3. Open a Microsoft support case for Copilot, explicitly describing it as an account‑specific failure that began after creating/deleting an AI agent and that does not repro with other accounts.
4. Ask for escalation if first‑line troubleshooting (cache, device, network, sign‑out/in, etc.) does not resolve it, because similar Copilot issues in the context were only fixed after escalation and backend changes by Microsoft.

No supported client‑side workaround or repair procedure for this specific corruption scenario is documented in the provided context.

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References:

• Copilot is missing, disabled, or doesn't work correctly
• FAQ about Copilot in Dynamics 365 Sales
• Understand error codes
• Use Copilot to analyze automation activity and ask product questions
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• Microsoft 365 Copilot Retrieval API errors with Authorization Failed - User does not have valid license - Microsoft Q&A
• Unable to log into m365.cloud.microsoft, something went wrong - Microsoft Q&A