Room cannot verify the data integrity in Android

If you're only developing the application at the moment, it means that you are not on Production and uninstalling the app from device and install it again will work as required.

Android 6.0+

For those of you who come across this now a days, simply uninstalling might not help and it will drive you nuts, so before you have to figure it out, let me share the issue: Google introduced the "autobackup" functionality in Android 6.0, which brings back a DB when you reinstall. (https://developer.android.com/guide/topics/data/autobackup.html)

You can simply add...

<application ...
    android:allowBackup="false">
</app>

...to disable this functionality and you are good to go (now you can simply uninstall to delete the database).