Coding⏱️ 2 min read📅 2026-05-30

How to Fix: Why does the error "[ksp] java.lang.IllegalStateException: unexpected jvm signature V" occur when using Room with KSP and how can I solve it?

Kotlin Room database error with KSP and JVM signature V. Commenting out code solves the issue.

Quick Answer: The error occurs due to a conflict between Kotlin's JVM signature version and the version used by Room. Disabling KSP or updating the JVM signature can resolve the issue.

The error '[ksp] java.lang.IllegalStateException: unexpected jvm signature V' occurs when using Room with KSP because of a mismatch between the JVM version used by KSP and the one expected by the Room library. This issue is often caused by the presence of the 'java.version' property in the build.gradle file, which specifies the target JVM version for the project.

✅ Best Solutions to Fix It

Method 1: Update JVM Version in build.gradle

  1. Step 1: Open the build.gradle file of your project and update the 'javaVersion' property to a compatible version, such as '11' or '8'. This will ensure that KSP uses a JVM version that is compatible with Room.

Method 2: Use the 'kotlin-jvm' plugin with a specific JVM version

  1. Step 1: In your build.gradle file, add the 'kotlin-jvm' plugin and specify a specific JVM version, such as '11' or '8'. This will ensure that KSP uses a JVM version that is compatible with Room.

🎯 Final Words

By following these methods, you should be able to resolve the '[ksp] java.lang.IllegalStateException: unexpected jvm signature V' error and successfully use Room with KSP in your project.

Did this fix your problem?

If not, try searching for specific error codes.

🔍 Search Error Database

❓ Frequently Asked Questions