Error9 reports
Fix NotImplementedError
in Unsloth
✅ Solution
The "NotImplementedError" in Unsloth usually arises when a specific feature or combination of features (like fast_inference with full_finetuning) hasn't been fully implemented yet for the chosen model or configuration. To fix it, either avoid using the unsupported feature combination (e.g., set `fast_inference = False` if you're using `full_finetuning = True`), choose a different Unsloth-compatible model that supports the desired features, or check for updates to Unsloth, as the feature might be implemented in a newer version. Often, the error message itself will suggest the feature causing the problem explicitly.
Related Issues
Real GitHub issues where developers encountered this error:
[Bug] Gemma 3n - maximum recursion depth exceededNov 28, 2025
NotImplementedError when loading gpt-oss-20b-unsloth-bnb-4bit with FastLanguageModelNov 11, 2025
[Feature] NotImplementedError: Unsloth: `fast_inference = True` does not yet support `full_finetuning = True`Nov 11, 2025
[Bug] No GPU detected when following DGX Spark ManualNov 4, 2025
ImportError: Unsloth: Please install unsloth_zoo via `pip install unsloth_zoo`Oct 27, 2025
Timeline
First reported:Sep 27, 2025
Last reported:Nov 28, 2025