Trouble with creating a data file in build

The data file will not created in my build, but it will be created when it is in Unity. I tried changing the location where the file will be created. Did not change the outcome. The code is in C#. Do I need to give my game permission to write a data file when it is in a build?

     using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     using UnityEngine.SceneManagement;
     using UnityEngine.UI;
     using System;
     using System.IO;
     using System.Linq;
     using System.Runtime.Serialization.Formatters.Binary;
          public List LoadPreviousTimes()
          {
             try
             {
                 var levelName = Path.GetFileName(selectedLevel).Replace(".json","");
                 var scoresFile = Application.persistentDataPath + "/" + playerName + "_" + levelName + "_times.dat";
                 using (var stream = File.Open(scoresFile, FileMode.Open))
                 {
                     var bin = new BinaryFormatter();
                     var times = (List<PlayerTimeEntry>)bin.Deserialize(stream);
                     return times;
                 }
             }
             catch(IOException ex)
             {
                 Debug.LogWarning("Couldn't load previous times for: " + playerName + ". Excetion: " + ex.Message);
                 return new List<PlayerTimeEntry>();
             }
         }
     
         public void SaveTime(deci
 
 mal time)
     {
         playerName = PlayerPrefs.GetString("PlayerName");
         var times = LoadPreviousTimes();
 
         var newTime = new PlayerTimeEntry();
         newTime.entryDate = DateTime.Now;
         newTime.time = time;
 
         var bFormatter = new BinaryFormatter();
         var levelName = Path.GetFileName(selectedLevel).Replace(".json","");
         var filePath = Application.persistentDataPath + "/" + playerName +"_"+ levelName + "_times.dat";
         using (var file = File.Open(filePath, FileMode.Create))
         {
             times.Add(newTime);
             bFormatter.Serialize(file, times);
         }
     }

API Compatibility Level problem. Just had to change it.