Document or section may not begin with a transition

[chengjun]

/Users/datalab/github/statsbook/2-2-认识Jupyter-Notebook.ipynb:50007: WARNING: Document or section may not begin with a transition.
WARNING: Execution Failed with traceback saved in /Users/datalab/github/statsbook/_build/html/reports/2-3-Python编程基础.log
WARNING: Execution Failed with traceback saved in /Users/datalab/github/statsbook/_build/html/reports/3-7-参数估计.log
WARNING: Execution Failed with traceback saved in /Users/datalab/github/statsbook/_build/html/reports/7-3-Python中的Ridge回归与Lasso回归.
log

[chengjun]

Solved by adjusting the hierarchy of titles.