In order to create my first, simple Kotlin project in Eclipse, I followed the steps in Getting Started with Eclipse Luna tutorial from Kotlin official website, i.e.:
I got same issues as you. I tried a lot of ways but not work (like uninstall plugin, then install plugin again, delete project and create new project...)
How to fix: I created a new workspace and setup the helloworld project again. I see that class file generated and I can run it normally.
Note that, we create new workspace and not project. What I notice is workspace contain .metadata folder that may have lot of information for Eclipse.