Conflicting cross-version suffixes (sbt, Scala-STM, Play-JSON)

Question

I am using a JSON extension which relies on Mandubian\'s play-json 2.2-SNAPSHOT. Everything worked fine until now I have a project based on Scala-STM. sbt reports the following

Answer 1

You can get around this by removing scala-stm with exclude

 "dependencyGroupId" %% "dependencyArtifactId" % "dependencyVersion" exclude("org.scala-stm", "scala-stm_2.10.0")

Do not forget to do sbt clean.