IntelliJ Idea 2017.3 unable to start Kotlin Spring Boot App - @Configuration class may not be final

Question

I was able to launch a Spring Boot Kotlin App from IntelliJ 2017.3. After the last IntelliJ fix update I cannot start that application from the IDE, getting this exception:<

Answer 1

If you get this error on IntelliJ, even with kotlin-spring plugin, you may want to check if the annotation processing has been enabled in IntelliJ.