Building and customizing solutions using Microsoft 365 Copilot APIs and tools
The model selector has not been removed; a blank “Select your agent’s model” card like the one shown matches a reported late-October 2026 issue affecting some newly created Copilot Studio agents.^1^
Confirm whether this is the reported regression
- Open an older agent in the same Copilot Studio environment.
- Compare its model control:
- Older agent has models, new agent is blank: this matches the reported new-agent regression. Avoid rebuilding the agent or changing tenant policies; retry later and report it to Microsoft if it remains blank.
- All agents are blank: check the agent experience and environment controls below.
- The warning displayed elsewhere on the Overview page is not enough to identify the cause. Select Review and handle it separately unless its message explicitly concerns model availability.
Copilot Studio still officially supports selecting a primary model for generative orchestration. For a standard-harness agent, the control belongs on the agent’s Overview page, which is exactly where the empty card appears in the screenshot.^2^
Check which agent experience is in use
The selector is located differently in the newer GitHub Copilot harness:
- Open the agent.
- Select Build.
- In the components panel, open Model.
- Choose a model and select Save.^3^
If this agent uses the standard harness—as the screenshot’s Overview card suggests—the expected location remains Overview → Select your agent’s model.
Conditional availability checks
If the picker loads but only certain models are missing, that is a different issue from the completely blank card:
- Model availability varies by region, release status, cross-geo settings, and agent harness.
- Preview and experimental models can require environment-level approval and cross-region data movement.
- The default model remains available as a fallback when a previously selected model is unavailable.^2^
If only external providers such as Anthropic, Mistral, or xAI are absent, ask the Power Platform/Microsoft 365 administrator to verify external-model access. Those providers require separate environment and provider controls; blocking them does not by itself explain an entirely empty standard model picker.^4^
If it remains blank
Open a Microsoft support request and include:
- Environment and tenant region
- Agent name and whether it is newly created
- Whether older agents in the same environment still show models
- Agent harness/experience
- Approximate time the selector disappeared
- The screenshot
- Browser network trace/HAR only if Support requests it
This gives Support enough information to distinguish the current new-agent regression from regional rollout or tenant controls.
References