xcodeのbreakpoint 1.1について

現在、swiftにてSNSを作成しているのですが、タイムラインを更新して投稿を読み込もうとするとタイムライン上でエラー（breakpoint 1.1）が起こりsimulatorが強制終了してしまいます。
ネットで調べても原因が分からず、自分ではどうしようもない状況です。
タイムラインと投稿ページのコードを記載いたしますので、もし原因が分かる方がいらしたら是非とも回答のほどよろしくお願いします。

swift
1import UIKit
2import Firebase
3import FirebaseDatabase
4import SDWebImage
5
6class TimeLineViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
7    
8    @IBOutlet weak var tableView: UITableView!
9    
10    var posts = [Post]()
11    var posst = Post()
12    
13    var fullName_Array = [String]()
14    var userImage_Array = [String]()
15    var comment_Array = [String]()
16    
17    let refleshControl = UIRefreshControl()
18    
19
20    override func viewDidLoad() {
21        super.viewDidLoad()
22
23        tableView.delegate = self
24        tableView.dataSource = self
25        
26        refleshControl.attributedTitle = NSAttributedString(string: "引っ張って更新")
27        refleshControl.addTarget(self, action: #selector(reflesh), for: UIControlEvents.valueChanged)
28        tableView.addSubview(refleshControl)
29        
30        self.tableView.estimatedRowHeight = 90
31        self.tableView.rowHeight = UITableViewAutomaticDimension
32    }
33
34    override func didReceiveMemoryWarning() {
35        super.didReceiveMemoryWarning()
36        // Dispose of any resources that can be recreated.
37    }
38    
39    func fetchPosts() {
40        
41        self.posts = [Post]()
42        self.fullName_Array = [String]()
43        self.userImage_Array = [String]()
44        self.comment_Array = [String]()
45        self.posst = Post()
46        
47        let ref = Database.database().reference()
48        
49        ref.child("post").queryOrderedByKey().observeSingleEvent(of: .value) { (snap) in
50            
51            let postsSnap = snap.value as? [String:NSDictionary]
52            if postsSnap == nil {
53                return
54            }
55            self.posts = [Post]()
56            for (_, post) in postsSnap! {
57                
58                self.fullName_Array = [String]()
59                self.userImage_Array = [String]()
60                self.comment_Array = [String]()
61                self.posst = Post()
62                
63                if let comment = post["comment"] as? String, let userName = post["fullName"] as? String, let userImage = post["userImage"] as? String{
64                    
65                    self.posst.comment = comment
66                    self.posst.fullName = userName
67                    self.posst.userImage = userImage
68                    
69                    self.comment_Array.append(self.posst.comment)
70                    self.fullName_Array.append(self.posst.fullName)
71                    self.userImage_Array.append(self.posst.userImage)
72                    
73                    
74                }
75                
76                self.posts.append(self.posst)
77                
78            }
79            self.tableView.reloadData()
80        }
81        
82    }
83    
84    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
85        return posts.count
86    }
87    
88    func numberOfSections(in tableView: UITableView) -> Int {
89        return 1
90    }
91    
92    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
93        
94        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) // breakpoint 1.1（ここで止まります）
95        
96        // 画像
97        let profileImageView = cell.viewWithTag(1) as! UIImageView
98        let profileImageUrl = URL(string: self.posts[indexPath.row].userImage as String)!
99        profileImageView.sd_setImage(with: profileImageUrl)
100        profileImageView.layer.cornerRadius = 8.0
101        profileImageView.clipsToBounds = true
102        
103        // ユーザーネーム
104        let userNameLabel = cell.viewWithTag(2) as! UILabel
105        userNameLabel.text = self.posts[indexPath.row].fullName
106        
107        // コメント
108        let commentLabel = cell.viewWithTag(3) as! UILabel
109        commentLabel.text = self.posts[indexPath.row].comment
110        commentLabel.sizeToFit()
111        
112        return cell
113    }
114    
115    @objc func reflesh() {
116        
117        fetchPosts()
118        refleshControl.endRefreshing()
119    }
120    
121
122    
123}
124

swift
1import UIKit
2import Firebase
3import FirebaseDatabase
4
5class PostViewController: UIViewController, UITextViewDelegate {
6    
7    @IBOutlet weak var textView: UITextView!
8    @IBOutlet weak var postButton: UIButton!
9    
10    var fullName_Array = [String]()
11    var userImage_Array = [String]()
12    var comment_Array = [String]()
13    
14    var fullName = String()
15    var profileImage: URL!
16    var passImage = UIImage()
17    
18    var userName = String()
19    
20    override func viewDidLoad() {
21        super.viewDidLoad()
22        
23        textView.delegate = self
24
25        textView.layer.borderColor = UIColor.black.cgColor
26        textView.layer.borderWidth = 1.0
27        
28        textView.layer.cornerRadius = 10.0
29        textView.layer.masksToBounds = true
30        
31        postButton.layer.cornerRadius = 20.0
32    }
33    
34    override func viewWillAppear(_ animated: Bool) {
35        super.viewWillAppear(animated)
36        let ud = UserDefaults.standard
37        
38        self.userName = ud.object(forKey: "userName") as! String
39        
40    }
41    
42    func postData() {
43        
44        let rootRef = Database.database().reference(fromURL: "https://kidoairaku17.firebaseio.com/").child("post")
45        let storage = Storage.storage().reference(forURL: "gs://kidoairaku17.appspot.com")
46        let key = rootRef.child("User").childByAutoId().key
47        let imageRef = storage.child("Users").child("(key).jpeg")
48        
49        let data:NSData = NSData() 
50        
51        let uploadTask = imageRef.putData(data as Data, metadata: nil) { (metadata, error) in
52            
53            if error != nil {
54                return
55            }
56            
57            imageRef.downloadURL(completion: { (url, error) in
58                
59                if url != nil {
60                    
61                    let feed = ["userImage":url?.absoluteString as Any, "comment":self.textView.text, "fullName":self.userName] as [String:Any] 
62                    let postFeed = ["(key)":feed] 
63                    rootRef.updateChildValues(postFeed) 
64                    
65                }
66            })
67        }
68        uploadTask.resume()
69    }
70    
71    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
72        textView.resignFirstResponder()
73    }
74
75    override func didReceiveMemoryWarning() {
76        super.didReceiveMemoryWarning()
77        // Dispose of any resources that can be recreated.
78    }
79    
80    @IBAction func postButtonTapped(_ sender: Any) {
81        postData()
82        self.dismiss(animated: true, completion: nil)
83    }
84    
85    
86    
87
88}
89