I have installed IDEA 2018.3 and my project is broken ever since. IDEA compalins that

Compilation is not supported for following modules: zircon.core_commonMain, zircon.core_commonTest, zircon.core_jvmMain, zircon.core_jvmTest. Unfortunately you can't have non-Gradle Java modules and Android-Gradle modules in one project.

what could be the problem? Gradle build runs fine, the application works, and it worked in the previous IDEA version as well. What do I need to upgrade to get this fixed? I'm not even using Android (have nothing Android-related on my computer). What's really weird is that I have neither non-Gradle Java modules nor Android-Gradle modules!

I often find re-importing the project into IDEA fixes this issue

got it, thanks!

You might check if delegating builds to Gradle setting is still there