There are missing plots in the docs, for example here:
https://optuna.readthedocs.io/en/stable/reference/visualization/generated/optuna.visualization.plot_edf.html

Tried on Chrome and Firefox, same story.
@dankal444 As a temporal solution to see the plots, you can check the latest document instead of the stable version.
For example https://optuna.readthedocs.io/en/latest/reference/visualization/generated/optuna.visualization.plot_edf.html
@dankal444 Thanks for raising an issue and @nzw0301 thanks for the comment. I agree with @nzw0301. This problem has been fixed in the master branch. Starting with the next release v2.3.0, plots in the documentation will be displayed properly.
Let me close this issue because the original problem is fixed in the master branch.
Most helpful comment
@dankal444 Thanks for raising an issue and @nzw0301 thanks for the comment. I agree with @nzw0301. This problem has been fixed in the master branch. Starting with the next release v2.3.0, plots in the documentation will be displayed properly.