If you import world generation settings and it shows the "Warning! these settings are using experimental features" screen you cant click on "Yes" as nothing happens. but clicking no applies the settings.

To reproduce:
Create a new world with generic settings, then click on edit after the world is created, then click on "export world generation settings", then create a new world and in the "More world options..." area click on import settings, after you import the settings on the previous world, you will see the experimental features screen where you cannot click yes but only no.

Expected result:
Clicking yes would apply the settings and clicking no would revert to the default settings.