There have been a lot of issues over the past year or so getting Room working in your standard Android project. A lot of different tools work together in order to make everything work. In order to get everything to work together, I recommend using the latest Android SDK versions in your project (covered in Chapter 8), using the latest versions of the Android Gradle plugin and the Kotlin Gradle plugin, using Java 17 for compiling your app (Java versions in Android builds | Android Studio | Android Developers), and using the latest version of the Room library.