ReactiveAndroid | Reactive events and properties with RxJava | Reactive Programming library

True, but the reason I chose ReactiveAndroid is to migrate from ActiveAndroid. Realm doesn't use SQLite which means the migration process would be more involved.

I found how to fix this problem:

DatabaseConfig appDatabase = new DatabaseConfig.Builder(AppDatabase.class) .addModelClasses(LogEntry.class) .addMigrations(AppDatabase.MIGRATION_16_17) .build();

You have to call addModelClasses. There is also some documentation that helped with subsequent errors that cropped up: https://imangazalievm.gitbooks.io/reactiveandroid/migration-from-activeandroid.html