Ollama Runner Crash Under Sustained Multi-Turn Tool-Calling on macOS Apple Silicon

What this error means

model runner has unexpectedly stopped / llama runner process has terminated is a Ollama failure pattern reported for developers trying to fix ollama crash during multi-turn tool-calling on macos apple silicon. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue (updated 2026-05-04). Ollama 0.20.5 on macOS Apple Silicon crashes reliably under sustained multi-turn tool-calling. Crash rate 72% across 7 tested models. Error: ‘model runner has unexpectedly stopped’. Critical for agentic AI workflows.

Common causes

• Ollama users on Apple Silicon experience reliable crashes during sustained multi-turn tool-calling conversations. The crash occurs mid-conversation with error ‘model runner has unexpectedly stopped’, disrupting agent workflows and MCP integrations.
• GitHub issue (updated 2026-05-04). Ollama 0.20.5 on macOS Apple Silicon crashes reliably under sustained multi-turn tool-calling. Crash rate 72% across 7 tested models. Error: ‘model runner has unexpectedly stopped’. Critical for agentic AI workflows.

Quick fixes

1. Confirm the exact error signature matches model runner has unexpectedly stopped / llama runner process has terminated.
2. Check the Ollama account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/ollama/ollama/issues/15923

Evidence note: GitHub issue (updated 2026-05-04). Ollama 0.20.5 on macOS Apple Silicon crashes reliably under sustained multi-turn tool-calling. Crash rate 72% across 7 tested models. Error: ‘model runner has unexpectedly stopped’. Critical for agentic AI workflows.

Related errors

• Ollama llama runner process has terminated
• Ollama MCP tool-calling crash

FAQ

What should I check first?

Start with the exact model runner has unexpectedly stopped / llama runner process has terminated text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Ollama workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without model runner has unexpectedly stopped / llama runner process has terminated.