Hello, i have a multi-module project:

include ':core'

include ':tech'

include ':rpg'

Core module is a base version for all modules(how library, but it's independed mod). Tech/Rpg module is a child of Core.

 

Using in builds scripts:

tech -> build.gradle

    implementation project(':core')

rpg -> build.gradle

    implementation project(':core')

 

And i have KotlinAdapter(yes, it's a mod written on Kotlin language), spoiler: this adapter work for core, but when a execute Intellij Idea task for run tech module("tech runClient") i take a exception with error: "adapter.kotlin.KotlinModContainer cannot be cast to net.minecraftforge.fml.ModContainer". But, when execute runClient(gradle task) it's work without of exception. How to i can execute Intellij Idea task for run my Tech and Rpg mods with Core mod in dependencies?

 

When run Intellij task "tech runClient" threads:

"Loading KotlinModContainer from classloader cpw.mods.modlauncher.TransformingClassLoader@47148f3f - got sun.misc.Launcher$AppClassLoader@18b4aac2"

When run Gradle task ":tech:runClient" threads:

"Loading KotlinModContainer from classloader cpw.mods.modlauncher.TransformingClassLoader@47148f3f - got cpw.mods.modlauncher.TransformingClassLoader@47148f3f"

 

You need to show your buildscript in question, but my assumption is that you don't have the kotlin container added to the runtime environment of the child projects.