How to use Scala in IntelliJ IDEA (or: why is it so difficult to get a working IDE for Scala)?I recently gave up trying to use Scala in Eclipse (basic stuff like completion doesn't work). So now I'm trying IntelliJ. I'm not getting very far. I've been able to edit programs (within syntax highlighting and completion... yay!). But I'm unable to run even the simplest "Hello World". This was the original error: Scala signature Predef has wrong version Expected 5.0 found: 4.1 in .... scala-libr
