How to create a matchmaking lobby

Hi, I have been trying to create a matchmaking lobby since a long time but I am getting some or the other error which I am unable to figure out.

I do not want to make use of database like sqlite or mysql.

I am stuck. Someone please suggest me a way to do so.

In desperation, I am attaching the entire script and relevant files of the lobby manager. Please help.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using Mirror;
 using System;
 using UnityEngine.SceneManagement;
 using System.Diagnostics;
 
 public class ConnectionManager : NetworkBehaviour
 {
     public GameObject PlayerClientSpace2;
     public GameObject PlayerServerSpace2;
     public GameObject PlayerMidSpace2;
     public bool joinserver2;
     public bool createserver2=true;
     public bool joinclient2;
     public List<int> UsedPorts = new List<int>();
 
     int port2;
     
     public override void OnStartServer()
     {
         
         PlayerClientSpace2 = GameObject.Find("PlayerClientSpace2");
         PlayerServerSpace2 = GameObject.Find("PlayerServerSpace2");
         PlayerMidSpace2 = GameObject.Find("PlayerMidSpace2");
         //LogicManager = GameObject.Find("LogicManager").GetComponent<LogicManager>();
         //LogicManager.createserver2 = true;
         base.OnStartServer();
     }
 
     public override void OnStartClient()
     {
         
         
         base.OnStartClient();
         if (hasAuthority)
         {
             if (GlobalScript.PlayerTotal == 2)
             {
                 if (GlobalScript.StartAs == "Client" && GlobalScript.PlayerTotal==2)
                 {
                     CmdPositionme(GlobalScript.StartAs, GlobalScript.PlayerTotal);
                 }
                 else if (GlobalScript.StartAs == "Server" && GlobalScript.PlayerTotal==2)
                 {
                     if (GlobalScript.ServerMatchMakingMode == "Ended")
                     {
                         CmdRemovePort(GlobalScript.Port);
                     }
                     else
                     {
                         CmdPositionme(GlobalScript.StartAs, GlobalScript.PlayerTotal);
                     }
                 }
             }
         }
     }
     [Command]
     void CmdPositionme(string StartAs, int PlayerTotal)
     {
         if (PlayerTotal == 2)
         {
             if (StartAs == "Client")
             {
                 transform.SetParent(PlayerClientSpace2.transform);
 
             }
             else if (StartAs == "Server")
             {
                 transform.SetParent(PlayerServerSpace2.transform);
 
             }
         }
     }
 
     [Command]
     void CmdRemovePort(uint port)
     {
         UsedPorts.Remove(Convert.ToInt32(port));
         TargetShutDownServer(connectionToClient);
     }
     
     [TargetRpc]
     void TargetShutDownServer(NetworkConnection conn)
     {
         Application.Quit();
     }
 
     // Start is called before the first frame update
     void Start()
     {
         
     }
 
     [TargetRpc]
     void TargetJoinServer2(NetworkConnection conn, int port)
     {
         
         GlobalScript.PlayerTotal = 2;
         GlobalScript.WinningScore = 7;
         GlobalScript.Port = Convert.ToUInt16(port);
         GlobalScript.StartServerClient = true;
         SceneManager.LoadScene("MainGame");
     }
 
     
 
     [TargetRpc]
     void TargetJoinClients2(NetworkConnection conn, int port)
     {
         GlobalScript.PlayerTotal = 2;
         GlobalScript.WinningScore = 7;
         GlobalScript.Port = Convert.ToUInt16(port);
         GlobalScript.networkAddress = "localhost";
         GlobalScript.StartServerClient = true;
         SceneManager.LoadScene("MainGame");
     }
 
    
 
     // Update is called once per frame
     void Update()
     {
         if (isServer)
         {
 
             if (PlayerClientSpace2.transform.childCount >= 2 && PlayerMidSpace2.transform.childCount == 0 && PlayerServerSpace2.transform.childCount>=1)
             {
                 GameObject G1 = PlayerClientSpace2.transform.GetChild(0).gameObject;
                 
                 GameObject G2 = PlayerClientSpace2.transform.GetChild(1).gameObject;
                 GameObject G3 = PlayerServerSpace2.transform.GetChild(0).gameObject;
 
                 G1.tag = "Client";
                 G2.tag = "Client";
                 G3.tag = "Server";
                 G3.transform.SetParent(PlayerMidSpace2.transform);
                 G1.transform.SetParent(PlayerMidSpace2.transform);
                 G2.transform.SetParent(PlayerMidSpace2.transform);
                 
                 
 [link text][1]
             }
 
             if(PlayerMidSpace2.transform.childCount==3 && joinserver2)
             {
                 joinserver2 = false;
                 for (var i=0; i<PlayerMidSpace2.transform.childCount; i++)
                 {
                     if(PlayerMidSpace2.transform.GetChild(i).gameObject.tag=="Server")
                     {
                         port2=70000;
                         
                         while(!UsedPorts.Contains(port2))
                         {
                             port2++;
                         }
                         UsedPorts.Add(port2);
                         createserver2 = true;
                         TargetJoinServer2(PlayerMidSpace2.transform.GetChild(i).gameObject.GetComponent<ConnectionManager>().connectionToClient, port2);
 
                     }
                 }
             }
 
             if (PlayerMidSpace2.transform.childCount == 2 && joinclient2)
             {
                 joinclient2 = false;
                 bool checkserver = false;
                 for (var i = 0; i < PlayerMidSpace2.transform.childCount; i++)
                 {
                     if (PlayerMidSpace2.transform.GetChild(i).gameObject.tag == "Server")
                     {
                         checkserver = true;
 
                     }
                 }
                 if(!checkserver)
                 {
                     joinserver2 = false;
                     for (var i = 0; i < PlayerMidSpace2.transform.childCount; i++)
                     {
                         TargetJoinClients2(PlayerMidSpace2.transform.GetChild(i).gameObject.GetComponent<ConnectionManager>().connectionToClient, port2);
                     }
                 }
                 else
                 {
 
                     joinclient2 = true;
                 }
             }
 
 
             if (PlayerMidSpace2.transform.childCount==0)
             {
                 joinserver2 = true;
                 joinclient2 = true;
 
             }
 
            
 
             if(PlayerServerSpace2.transform.childCount==0 && createserver2)
             {
                 createserver2 = false;
                 Process startserver = new Process();
                 startserver.StartInfo.FileName = "C:\\Users\\ankit\\TopCat\\Builds\\TopCat.exe";
                 startserver.StartInfo.Arguments = "server2";
                 startserver.Start();
             }
 
             
             
         }
     }
 }

[1]: /storage/temp/161023-files.zip