when I run the airbnb example with

yarn dev

I get

Schema must be an instance of GraphQLSchema. Also ensure that there are not multiple versions of GraphQL installed in your node_modules directory.

I think it has something todo with my setup but I don’t know where to look

can you create a bug report: https://github.com/graphcool/graphql-server-example? 🙂

@rick Even I was facing similar issue. Doing

npm install graphql@latest

fixed it.