Не удалось открыть файл базы данных

При переходе в activity, в которой находится БД выскакивает ошибка: Unable to open the database file. Код данной activity

package com.example.chernovik;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;


public class ActivityList extends AppCompatActivity {
    TextView txtListView;
    Button b1;
    Button b2;
    Button b3;
    EditText eT;
    ListView listView;
    DataBaseHelper databaseHelper;
    SimpleCursorAdapter userAdapter;
    Cursor userCursor;
    SQLiteDatabase db_sort;
    long userId=0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);
        b1 = findViewById(R.id.b1);
        txtListView = findViewById(R.id.txtListView);
        Intent intent = getIntent();
        String outputString = intent.getStringExtra("name");
        txtListView.setText(outputString);
        databaseHelper = new DataBaseHelper(getApplicationContext());

        //создаём БД
       databaseHelper.create_db();
    }
@Override
public void onResume() {
    super.onResume();
// открываем подключение
    db_sort = databaseHelper.open();
    //получаем данные из бд в виде курсора
    userCursor =  db_sort.rawQuery("select * from "+ DataBaseHelper.TABLE, null);
    // определяем, какие столбцы из курсора будут выводиться в ListView
    String[] headers = new String[]{DataBaseHelper.COLUMN_NAME};
    // создаем адаптер, передаем в него курсор
    userAdapter = new SimpleCursorAdapter(this, android.R.layout.two_line_list_item,
            userCursor, headers, new int[]{android.R.id.text1}, 0);
    listView.setAdapter(userAdapter);

    b1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            ContentValues cv = new ContentValues();
            cv.put(DataBaseHelper.DB_NAME, String.valueOf(eT.getText()));
            db_sort.update(DataBaseHelper.TABLE, cv, DataBaseHelper.COLUMN_ID + "=" + String.valueOf(userId + 1), null);
            userId = userId + 1;
            db_sort.insert(DataBaseHelper.TABLE, null, cv);
        }
    });
    b2 = findViewById(R.id.b2);
    b2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            db_sort.delete(DataBaseHelper.TABLE, "_id = ?", new String[]{String.valueOf(userId)});
        }
    });
    b3 = findViewById(R.id.b3);
    b3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            try {
                databaseHelper.close();
                userCursor.close();
                finish();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}
        }

А так же ниже приведу код использования уже существующей БД

package com.example.chernovik;
import android.database.SQLException;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase;
import android.content.Context;
import android.util.Log;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
class DataBaseHelper extends SQLiteOpenHelper {
    private static String DB_PATH; // полный путь к базе данных
    static String DB_NAME = "AESDataBase.db";
    private static final int SCHEMA = 1; // версия базы данных
    static final String TABLE = "users"; // название таблицы в бд
    // названия столбцов
    static final String COLUMN_ID = "_id";
    static final String COLUMN_NAME = "name";
    private Context myContext;
    DataBaseHelper(Context context) {
        super(context, DB_NAME, null, SCHEMA);
        this.myContext=context;
        DB_PATH =context.getFilesDir().getPath();
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion,  int newVersion) {
    }
    void create_db(){
        InputStream myInput;
        OutputStream myOutput;
        try {
            File file = new File(DB_PATH);
            if (!file.exists()) {
                this.getReadableDatabase();
                //получаем локальную бд как поток
                myInput = myContext.getAssets().open(DB_NAME);
                // Путь к новой бд
                String outFileName = DB_PATH;
                // Открываем пустую бд
                myOutput = new FileOutputStream(outFileName);
                // побайтово копируем данные
                byte[] buffer = new byte[1024];
                int length;
                while ((length = myInput.read(buffer)) > 0) {
                    myOutput.write(buffer, 0, length);
                }
                myOutput.flush();
                myOutput.close();
                myInput.close();
            }
        }
        catch(IOException ex){
            Log.d("DatabaseHelper", ex.getMessage());
        }
    }
     SQLiteDatabase open()throws SQLException {
        return SQLiteDatabase.openDatabase(DB_PATH, null, SQLiteDatabase.OPEN_READWRITE);
    }
}

И лог самой ошибки

436-436/com.example.chernovik E/SQLiteDatabase: Failed to open database '/data/user/0/com.example.chernovik/files'.
                                                                   android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
                                                                   #################################################################
                                                                   Error Code : 14 (SQLITE_CANTOPEN)
                                                                   Caused By : Unable to open the database file.
                                                                    (unknown error (code 14): Could not open database)
                                                                   #################################################################
                                                                       at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
                                                                       at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:242)
                                                                       at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:203)
                                                                       at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:518)
                                                                       at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:209)
                                                                       at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:181)
                                                                       at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:1073)
                                                                       at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:1018)
                                                                       at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:824)
                                                                       at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:799)
                                                                       at com.example.chernovik.DataBaseHelper.open(DataBaseHelper.java:71)
                                                                       at com.example.chernovik.ActivityList.onResume(ActivityList.java:54)
                                                                       at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1277)
                                                                       at android.app.Activity.performResume(Activity.java:7058)
                                                                       at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3765)
                                                                       at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3828)
                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2991)
                                                                       at android.app.ActivityThread.-wrap14(ActivityThread.java)
                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1635)
                                                                       at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                       at android.os.Looper.loop(Looper.java:154)
                                                                       at android.app.ActivityThread.main(ActivityThread.java:6692)
                                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)
03-20 13:36:12.601 436-436/com.example.chernovik E/AndroidRuntime: FATAL EXCEPTION: main
                                                                   Process: com.example.chernovik, PID: 436
                                                                   java.lang.RuntimeException: Unable to resume activity {com.example.chernovik/com.example.chernovik.ActivityList}: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
                                                                   #################################################################
                                                                   Error Code : 14 (SQLITE_CANTOPEN)
                                                                   Caused By : Unable to open the database file.
                                                                    (unknown error (code 14): Could not open database)
                                                                   #################################################################
                                                                       at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3788)
                                                                       at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3828)
                                                                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2991)
                                                                       at android.app.ActivityThread.-wrap14(ActivityThread.java)
                                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1635)
                                                                       at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                       at android.os.Looper.loop(Looper.java:154)
                                                                       at android.app.ActivityThread.main(ActivityThread.java:6692)
                                                                       at java.lang.reflect.Method.invoke(Native Method)
                                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468)
                                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)
                                                                    Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
                                                                   #################################################################
                                                                   Error Code : 14 (SQLITE_CANTOPEN)
                                                                   Caused By : Unable to open the database file.
                                                                    (unknown error (code 14): Could not open database)
                                                                   #################################################################
                                                                       at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
                                                                       at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:242)
                                                                       at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:203)
                                                                       at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:518)
                                                                       at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:209)
                                                                       at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:181)
                                                                       at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:1073)
                                                                       at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:1018)
                                                                       at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:824)
                                                                       at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:799)
                                                                       at com.example.chernovik.DataBaseHelper.open(DataBaseHelper.java:71)
                                                                       at com.example.chernovik.ActivityList.onResume(ActivityList.java:54)
                                                                       at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1277)
                                                                       at android.app.Activity.performResume(Activity.java:7058)
                                                                       at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3765)
                                                                        ... 10 more