安卓存档问题 玩家反映会掉档

代码
public void SaveGame(){
gameDate.GameVer=1.11f;
if(!Directory.Exists(Application.persistentDataPath + "/Save")){ //如果存档目录不存在，则创建
Directory.CreateDirectory(Application.persistentDataPath + "/Save");
}
BinaryFormatter formatter = new BinaryFormatter(); //二进制转化
FileStream file= File.Create(Application.persistentDataPath + "/Save/SaveDate.sav");
var json=JsonUtility.ToJson(gameDate); //将SaveDate转化为字符串
formatter.Serialize(file,json);
file.Close();
}
public void LoadGame(){
BinaryFormatter bf = new BinaryFormatter();
if(File.Exists(Application.persistentDataPath + "/Save/SaveDate.sav")){ //如果存档存在
FileStream file = File.Open(Application.persistentDataPath + "/Save/SaveDate.sav",FileMode.Open);
JsonUtility.FromJsonOverwrite((string)bf.Deserialize(file),gameDate);
file.Close();
}