RealmでMigrationエラー

現在、SwiftでRealmを勉強中です。簡単なクイズアプリを作ってみようと思い、CSVをRealm Browserにインポートしdefault.realmを作成しました。
まず始めに問題文(Q)をデバッグエリアに表示させようと思ったのですが、エラーになりました。
エラー内容を見る限り、Migrationに関するエラーだと思うのですが、色々サイトを見ても解決方法が理解できませんでした。
どなたか助けていただけるとありがたいです。

import UIKit
import RealmSwift

class realm_test:Object {
    dynamic var Q:String = ""
    dynamic var A1:String = ""
}

class ViewController: UIViewController {

    private var Questions:[String] = []

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        getAllQuestions()

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    func getAllQuestions() {
        let config = Realm.Configuration(
            fileURL: NSBundle.mainBundle().URLForResource("default", withExtension: "realm"),
            readOnly: true)

        let realm = try! Realm(configuration: config)

        let results = realm.objects(realm_test).filter("Q != ''")

        for i in 0 ..< results.count {
            Questions.append(results[i].Q)
        }

        print("getAllQuestions=\(results)")
    }


}

エラー

fatal error: 'try!' expression unexpectedly raised an error: Error Domain=io.realm Code=10 "Migration is required due to the following errors:
- Property 'A2' is missing from latest object model.
- Property 'A3' is missing from latest object model.
- Property 'A4' is missing from latest object model.
- Property 'A5' is missing from latest object model." UserInfo={NSLocalizedDescription=Migration is required due to the following errors:
- Property 'A2' is missing from latest object model.
- Property 'A3' is missing from latest object model.
- Property 'A4' is missing from latest object model.
- Property 'A5' is missing from latest object model., Error Code=10}: file /Library/Caches/com.apple.xbs/Sources/swiftlang/swiftlang-703.0.18.8/src/swift/stdlib/public/core/ErrorType.swift, line 54

default.realm