Notebook fails to render on GitHub with “Invalid notebook” error

[null0NULL123]

Description

GitHub fails to render one or more Jupyter notebooks (.ipynb) with the message “Invalid notebook,” even though the files open and run correctly in VS Code/Jupyter locally.

Affected Files

• Own_reasoning_model_with_GRPO.ipynb
• Potentially other .ipynb files in the repository.

Suspected Cause

The GitHub notebook renderer rejects the file due to strict nbformat/JSON schema validation

[Adityarya11]

Hi sir, I am new to open source and would love to fix this jupyter notebook rendering issue for Hacktoberfest.

I found and fixed the "Invalid Notebook" error. I've forked the repo and tried to fix the issue in my separate branch. I’ve run validation locally and added two small scripts (scripts/fix_notebooks.py and scripts/validate_nb.py) to reproduce the fix.

Could I be assigned this issue? I’m ready to open a PR (already pushed to branch adi/fix_issue#200 on my fork). Thanks!