This may be due to a broken publication of org.jetbrains:sbt-structure:latest.integration that occurred tonight, about 4 or 5 hours ago.  Given that your post is 4 hours old ...
You can see the ivy activity in idea.log (~/Library/Logs/IntelliJIdea13 or ~/Library/Logs/IdeaIC13 on OSX). 
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]  ::          UNRESOLVED DEPENDENCIES         ::
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]  :: org.jetbrains#sbt-structure;latest.integration: not found
[warn]  ::::::::::::::::::::::::::::::::::::::::::::::
[warn]
[warn]  Note: Some unresolved dependencies have extra attributes.  Check that these dependencies exist with the requested attributes.
[warn]          org.jetbrains:sbt-structure:latest.integration (sbtVersion=0.13, scalaVersion=2.10)
I have opened a ticket at JetBrains.