[vanilla] Can't get any mods to work

[LilyPadma]

I have installed 5 mods which are supposed to be compatible with Vanilla. They appear in the mod menu and are checked. But after I click "Next," the only option available is "Back." Why can't I advance to start the game?

 

[Troller0001]

The "Single Player" text that looks like a header is actually a button. Click it to advance to the setup menu

 

[LilyPadma]

Thank you!!!