Are you doing "sbt idea" or "play idea?" From what I recall, "sbt idea" was broken, while doing it using the play launcher works, as they have some broken dependencies.

I use sbt idea. I can try play, but it would be great if it just worked.

Thing is, it does just work...if you follow the directions Play gives you once you create a new project. Namely, to use their play wrapper around sbt.

(I am not saying this is a good idea, but I am saying it "just works".)