Troubleshoot Simulink Copilot Errors

Use this topic to diagnose and resolve errors you might encounter when using Simulink® Copilot. This topic includes a general troubleshooting workflow and a list of error categories with the exact error messages shown in the product and recommended actions you can try before contacting MathWorks® Technical Support.

Most Simulink Copilot errors are caused by an outdated MathWorks Service Host. For best results, use the latest version of MathWorks Service Host version. Connecting to internet automatically upgrades the MathWorks Service Host to the latest version. If your system restricts updates (for example, due to admin controls), you might need help from your IT administrator. If you need assistance, contact MathWorks Technical Support.

General Troubleshooting Workflow

If Simulink Copilot is unable to connect to the required services, you may see the error messages similar to the following in the Copilot Chat panel or the Diagnostic Viewer:

Unable to connect to Simulink Copilot services right now. Close the MATLAB session and end the MathWorks Service Host tasks.

To resolve this issue, follow these steps:

  1. Close the MATLAB session.

  2. Open your system’s process manager:

    • On Windows® platforms, open Task Manager and navigate to the Background processes section.

    • On Linux® platforms, open System Monitor and view the list of running background processes.

  3. Right-click each instance of MathWorks Service Host and click End task.

    End MathWorks Service Host processes

  4. If any slcopilotlocal processes are running, end them.

  5. Restart MATLAB and start a Simulink Copilot chat session.

If this workflow does not resolve the error, try the category-specific guidance in the next section.

Error Categories and Recommended Actions

The table maps each error category to the message you might see and recommended actions.

Error CategoryError messagePossible CausesRecommended Actions
Connection Issues (CONN) Unable to provide Simulink Copilot services right now.

  • Network is unavailable.

  • MathWorks Service Host is outdated.

  1. Get the latest version of MathWorks Service Host.

  2. Restart Simulink Copilot and submit your request.

Operation Timeout (TOUT)Unable to provide Simulink Copilot services right now.

  • MathWorks Service Host is outdated.

  • Request takes longer than expected to complete.

  1. Get the latest version of MathWorks Service Host.

  2. Rephrase your query or submit a simpler request.

Authentication or Permission Failure (AUTH)Your session expired or authorization failed. Please sign in again, then restart Simulink Copilot.

  • License is invalid or expired.

  • Authentication endpoints are unreachable.

  • Authentication session has expired.

  1. Confirm your license is valid and active.

  2. Check your network connection.

  3. Sign out of your MathWorks account, sign back in, and restart Simulink Copilot.

Initialization, Execution, or Unknown Errors (INIT, INPT, EXEC, CNFG, UNKNOWN)

  • Unable to provide Simulink Copilot services right now.

  • An unexpected error occurred. Please retry your request.

  • Your query maybe malformed or complex.

  • Unexpected issues.

  • MathWorks Service Host is outdated.

  1. Restart Simulink Copilot, then retry the query.

  2. If the issue persists, rephrase the query or submit a simpler request.

  3. Get the latest version of MathWorks Service Host.

Resource Limitation (ROUT)Unable to provide Simulink Copilot services right now.

  • Insufficient system memory.

  • Low disk space.

  • High CPU usage due to other applications.

  1. Check available system memory and disk space.

  2. If required, close other resource-intensive applications.

Rate Limiting Errors (RATE)Unable to provide Simulink Copilot services right now.

Request rate exceeds the allowed frequency.

Reduce the frequency of requests.

Data Streaming Issues (DATA)The response generation was interrupted. Retry your request.

  • Temporary network interruption.

  • Incomplete data transfer.

  • Response payload is too large.

  1. Check the stability of your internet connection.

  2. Retry the query or submit a simpler request.

Session Management Errors (SESS)Unable to process this request. Please try again.

  • Copilot session is stale.

  • Simulink Copilot session creation repeatedly fails.

Close Simulink Copilot, restart it, and retry the query.

MATLAB–MathWorks Service Host Synchronization Errors (SYNC) Unable to connect to Simulink Copilot services right now. Close the MATLAB session and end the MathWorks Service Host tasks. MATLAB cannot connect to MathWorks Service Host.Follow the General Troubleshooting Workflow . If the issue persists, get the latest version of MathWorks Service Host.
Clear History Errors (HIST)Unable to clear chat history. Please try again.Unexpected error during history cleanup.

  1. Retry clearing the chat history.

  2. If the issue persists, restart Simulink Copilot.

Chat Operation Errors (CHAT)Unable to process this request. Please try again.

  • Query is malformed or complex.

  • Internet connection was lost during the operation.

  1. Check your internet connection.

  2. Retry the query.

  3. If the issue persists, rephrase the query or submit a simpler one.

Request Cancellation Errors (CNCL) Unable to provide Simulink Copilot services right now. Retry your request.Cancellation operation does not work.If Simulink Copilot becomes unresponsive after cancellation, close and restart it.

Chat Panel Stuck in Loading State

If the chat panel remains in a loading state (for example, the spinner does not resolve and the panel does not become interactive), an outdated MathWorks Service Host is the most common cause of this issue. Connecting to internet upgrades the MathWorks Service Host to the latest version unless your have restricted admin control setup. If the issue persists, restart MATLAB and try again.

See Also

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