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

Updated Play2 2.2 - downgrading to SBT from 0.13.0 -> 0.12.4 didn't work with me, but excluding using exclude("org.scala-stm", "scala-stm_2.10.0") on ALL app-specific dependencies I had worked fine -- anyway -- none of my dependencies shouldn't have anything to do with scala-stm.