Cline error
Cline: Unexpected API Response: The language model did not provide any...
Unexpected API Response: The language model did not provide any assistant messages. This may indicate an issue with the API or the model's output.Status: WorkaroundLast verified 2 documented fixes3 sources
What it means
The provider returned a response containing no assistant content, so Cline had nothing to act on.
Causes
- Upstream provider outage: in #876 (OpenRouter, Claude 3.5 Sonnet) the maintainer attributed the error to an OpenRouter/Anthropic outage.
- Context window errors from OpenRouter/Cline provider with GPT-5 that were not parsed correctly before 3.26.2.
How to fix it
- Fix 1.
Check the provider's status and retry once the outage clears; the maintainer closed #876 after the OpenRouter/Anthropic outage ended.
- Fix 2.
Update Cline: 3.26.2 "Fix OpenRouter context window error handling to properly extract error codes from error messages, resolving "Unexpected API Response" errors with GPT-5 on Cline provider".
More Cline errors
All 17 Cline errorsShell Integration Unavailable. Cline may have trouble viewing the command's output. Please update VSCode (CMD/CTRL + Shift + P → "Update") and make sure you're using a supported shell: zsh, bash, fish, or PowerShell (CMD/CTRL + Shift + P → "Terminal: Select Default Profile").Status: WorkaroundError executing command: The command ran successfully, but we couldn't capture its output. Please proceed accordingly.Status: Fixed in releaseCommand failed with exit code 1: powershell (Get-CimInstance -ClassName Win32_OperatingSystem).caption 'powershell' is not recognized as an internal or external command, operable program or batch file.Status: WorkaroundInvalid API Response: The provider returned an empty or unparsable response. This is a provider-side issue where the model failed to generate valid output or returned tool calls that Cline cannot process. Retrying the request may help resolve this issue.Status: OpenModel returned empty responseStatus: OpenFunction call is missing a thought_signature in functionCall parts. This is required for tools to work correctly, and missing thought_signature may lead to degraded model performance.Status: Fixed in release429 {"type":"error","error":{"type":"rate_limit_error","message":"Number of request tokens has exceeded your per-minute rate limit (https://docs.anthropic.com/en/api/rate-limits); see the response headers for current usage. Please reduce the prompt length or the maximum tokens requested, or try again later. You may also contact sales at https://www.anthropic.com/contact-sales to discuss your options for a rate limit increase."}}Status: WorkaroundInvalid MCP settings format. Please ensure your settings follow the correct JSON format.Status: Workaround
Related reading
- What Is Cline? The Open-Source AI Coding Agent for VS CodeCline is a free, open-source VS Code extension for agentic AI coding. Bring your own model, a cloud API or a local one via Ollama, with no vendor lock-in.
- Every AI Coding Tool Compared: The 2026 MatrixEvery AI coding tool compared: 15 terminal, IDE, cloud and browser tools side by side on pricing, model surface, strengths, weaknesses and best use cases.
FAQ
What does "Unexpected API Response: The language model did not provide any..." mean in Cline?
The provider returned a response containing no assistant content, so Cline had nothing to act on.
How do I fix "Unexpected API Response: The language model did not provide any..."?
There are 2 documented fixes. Start with the first: Check the provider's status and retry once the outage clears; the maintainer closed #876 after the OpenRouter/Anthropic outage ended.
Is this Cline error fixed?
Status: Workaround. No release removes the cause. The documented fixes work around it. Affected versions: Reported Dec 2024 (pre-3.0); GPT-5 variant fixed in 3.26.2
Sources
Last verified against 3 sources: official docs, maintainer replies and release notes.
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