I have installed intelliJ-IDEA 2017.2.5 with scala plugin on Ubuntu 16.04LTS. When I create new scala project and try to run it I get:
Error:scalac:
In my case upgrading the Scala plugin via IntelliJ options made the trick.
It could be related to a fixed issue.
Go to Preferences, filter on Scala. (Plugins - Scala) click on Update. Restart IntelliJ.