The given key was not present in the dictionary, i am calling the key immediately after adding it

Here is the dictionaries i am calling from in the function

 public Dictionary<Vector2, GameObject> TilePos = new Dictionary<Vector2, GameObject>();
     public Dictionary<Vector2, GameObject> UnitPos = new Dictionary<Vector2, GameObject>();
     public Dictionary<Vector2, GameObject> BuildingPos = new Dictionary<Vector2, GameObject>();

Here is the function that the error originates from

 public void SaveMap(Dictionary<Vector2, GameObject> TP, Dictionary<Vector2, GameObject> UP,Dictionary<Vector2,GameObject> BP, string SaveName)
     {
         if (!System.IO.File.Exists(Application.dataPath + "/StreamingAssets/Saves/" + SaveName + ".dat"))
         {
             if (SaveName != "")
             {
                 if (!Regex.IsMatch(SaveName, @"^[a-z][A-Z]+$"))
                 {
                     Map save = new Map();
                     foreach (KeyValuePair<Vector2, GameObject> kvp in TP)
                     {
                         foreach (var kvvp in DBC.TerrainDictionary)
                         {
                             if (kvp.Value.transform.name == kvvp.Value.Title)
                             {
                                 save.TerrainPositions.Add(kvp.Key, kvvp.Value);
                             }
                         }
                     }
                     foreach (KeyValuePair<Vector2, GameObject> ukvp in UP)
                     {
                         if (ukvp.Value != null)
                         {
                             foreach (var keyvp in DBC.UnitDictionary)
                             {
                                 if (ukvp.Value.transform.name == keyvp.Value.Title)
                                 {
                                     save.UnitPosition.Add(ukvp.Key, keyvp.Value);
 
                                     //this errors, cant figure out why
                                     save.UnitPosition[ukvp.Key].Team = ukvp.Value.transform.GetComponent<SpriteController>().Team;
                                     //this errors, cant figure out why
                                 }
                             }
                         }
                     }
                     foreach (KeyValuePair<Vector2, GameObject> bkvp in BP)
                     {
                         if (bkvp.Value != null)
                         {
                             foreach (var kvp in DBC.BuildingDictionary)
                             {
                                 if (bkvp.Value.transform.name == kvp.Value.Title)
                                 {
                                     save.BuildingPositions.Add(bkvp.Key, kvp.Value);
                                     save.BuildingPositions[bkvp.Key].Team = bkvp.Value.transform.GetComponent<SpriteController>().Team;
                                 }
                             } 
                         }
                     }
                     string destination = Application.dataPath + "/StreamingAssets/Saves/" + SaveName + ".dat";
                     var fs = File.Create(destination);
                     BinaryFormatter bf = new BinaryFormatter();
                     bf.Serialize(fs, save);
                     fs.Close();
                     MEMCC.SaveFeedback.text = "File saved as: " + SaveName;  
                 }
                 else
                 {
                     MEMCC.SaveFeedback.text = "Only use letters";
                 }
             }
             else
             {
                 MEMCC.SaveFeedback.text = "Add a name.";
             }
         }
         else
         {
             MEMCC.SaveFeedback.text = "Current file name is already in use, please rename your save or delete old file.";
         }
     }

Here is the class for Map

 [Serializable]
 public class Map
 {
     public Dictionary<SeralizableVector2, Terrain> TerrainPositions = new Dictionary<SeralizableVector2, Terrain>();
     public Dictionary<SeralizableVector2, Unit> UnitPosition = new Dictionary<SeralizableVector2, Unit>();
     public Dictionary<SeralizableVector2, Building> BuildingPositions = new Dictionary<SeralizableVector2, Building>();
 }

This is my unique vector2 (unity vector2 are not serializable)

 [Serializable]
 public class SeralizableVector2
 {
     public float x;
     public float y;
 
     public SeralizableVector2(float rx,float ry)
     {
         x = rx;
         y = ry;
     }
 
     public static implicit operator Vector2 (SeralizableVector2 rValue)
     {
         Vector2 newVec = new Vector2(rValue.x, rValue.y);
         return newVec;
     }
 
     public static implicit operator SeralizableVector2(Vector2 Value)
     {
         return new SeralizableVector2(Value.x, Value.y);
     }
 }

Let me know if more info is needed. Any help is appreciated.