Not able to open pre-installed database using Sqlite AssetHelper library

I am working on pre-installed database and using SqliteAssetHelper library for that.

This is my db code

public class DBController extends SQLiteAssetHelper {

    private static final String DATABASE_NAME = "user.db";
    private static final int DATABASE_VERSION = 1;

    private final String TABLE_NAME = "User";

    public DBController(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    public ArrayList<UserData> getAllUserData() {

        ArrayList<UserData> data_list = new ArrayList<>();

        try {
            // open database to query
            SQLiteDatabase mySqliteDb = getWritableDatabase();

        } catch (Exception e) {

            Log.e("exception", "" + e);
        }

        close();
        return data_list;
    }
}

Error: Missing databases/user.db file (or .zip, .gz archive) in assets, or target folder not writable

and when I change my code to SQLiteDatabase mySqliteDb = getReadableDatabase(); I am getting android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database error.

I search for the problem and mostly everyon saying check your db present inside databases folder or not.

I tried using zip also still no luck. I guess I am missing something.