'List is empty' issue in Android Studio with Room

Question

I am creating an Android application, created Room, tried to run it but had this issue. Here is all my code: https://github.com/MaxImUm05-a/Educards

• What went wrong: Execution failed for task ':app:compileDebugJavaWithJavac'.

java.util.NoSuchElementException: List is empty.

I asked some AIs, looked through Internet. I reviewed and rewrote my Room code, did different changes in gradle.