This project shows problems with https://github.com/codingwell/scala-guice at version 4.2.2 and Play framework's dev mode.
Clone this project, start Play via sbt run
and point your browser to http://localhost:9000. You will see an exception.
Now downgrade the dependency to scala-guice in build.sbt to version 4.2.1. Cancel sbt
, restart and reload.