Some runtime JAR files in the classpath have an incompatible version. Consider removing them from the classpath

Question

I am getting the following error while building my android studio project.

Any idea how to resolve these?

Task :app:compileDebugKotlin w: Runtime JAR files in the classpath should have the same version. These files were found in the classpath: /Users/arpit/.gradle/caches/transforms-2/files-2.1/2f0acfdb5ca832ed018dc4bc38a13985/jetified-kotlin-stdlib-jdk8-1.3.61.jar (version 1.3) /Users/arpit/.gradle/caches/transforms-2/files-2.1/cf0b910eaf7d073f4207081a72f8fccf/jetified-kotlin-stdlib-jdk7-1.3.61.jar (version 1.3) /Users/arpit/.gradle/caches/transforms-2/files-2.1/7f0de453ba67b933d609d2948e77e8ae/jetified-kotlin-stdlib-1.4.10.jar (version 1.4) /Users/arpit/.gradle/caches/transforms-2/files-2.1/28dd71f1078961ee52c8b9a5ea1ba04a/jetified-kotlin-stdlib-common-1.4.10.jar (version 1.4) w: Some runtime JAR files in the classpath have an incompatible version. Consider removing them from the classpath

Screenshot

Answer 1

I'm facing the same warning in my backend project with Kotlin.

I've changed Kotlin version to 1.4.10 and warning starts to appears on each test run. Probably there is some transitive dependency that brings in classpath jars with an older version of Kotlin. In my case in classpath I've found kotlin-reflect 1.3.* that isn't required for the current project but Gradle when compiles take always the same class path from ~/.gradle and probably makes assumtion that something could go wrong in runtime. I've solved by adding kotlin-reflect dependency with the same version of Kotlin jvm target. It's ugly because I don't need kotlin-reflect but the warning has been desapeared and I'm happy about that.

Answer 2

Maybe there is a problem in your project structure.

In android studio File > Project Structure... > Modules > 'your_module_android' > Dependencies

Check the KotlinJavaRuntime box.