При выполнении функции clr я получаю ошибку NET framework error, возникшую во время выполнения пользовательской подпрограммы или агрегата "spexecuteparallel"

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Проблема
Я работаю на sql server 2012 при реализации функции clr я получаю ошибку

Msg 6522, Level 16, State 1, Line 1
A .NET Framework error occurred during execution of user-defined routine or aggregate "spExecuteParallel": 
System.NullReferenceException: Object reference not set to an instance of an object.
System.NullReferenceException: 
   at SqlStoredProcedureClr.spExecuteParallel(String DB, Int32 MaxDOP, String TSQL, Int32 msDelay, Int32 Retries)
.

он фактически выполняется один раз только для вставки и вставки данных но после этого отображается ошибка выше

select dbo.spExecuteParallel
( N'Test',8, N'Insert into TestTable (messagesData, LogDateValues) values (''Test'', GetDate())', 0, 1)

функция sql clr это

Create FUNCTION [dbo].[spExecuteParallel](@DB [nvarchar](200), @MaxDOP [int], @TSQL [nvarchar](4000), @msDelay [int], @Retries [int])
RETURNS [bigint] WITH EXECUTE AS CALLER, RETURNS NULL ON NULL INPUT
AS 
EXTERNAL NAME [StoredProcedures].[SqlStoredProcedureClr].[spExecuteParallel]

Что я уже пробовал:

public static class SqlStoredProcedureClr
{
 
        [SqlFunction(SystemDataAccess = SystemDataAccessKind.Read, DataAccess = DataAccessKind.Read)]
        public static SqlInt64 spExecuteParallel(string DB, int MaxDOP, string TSQL, int msDelay, int Retries)
        {
            // Initialize Variables
            SqlConnection oConn = new SqlConnection();
            SqlCommand oCmd = new SqlCommand();
            List<string> oErrorString = new List<string>();
            object oLocker = new object();
            string sServer = null;

            List<Thread> oThread = new List<Thread>();
            StringCollection sStopped = new StringCollection();

      
    
        oConn = new SqlConnection("context connection = true;");
        oConn.Open();

            oCmd = oConn.CreateCommand();
            oCmd.CommandText = "SELECT @@SERVERNAME";
            sServer = oCmd.ExecuteScalar().ToString();

            oCmd.Dispose();
            oConn.Close();
            oConn.Dispose();

            // Execute Threads
            int iCurrentThread = 0;
            while (iCurrentThread < MaxDOP)
            {
                ExecuteSQL Executer = new ExecuteSQL
                (sServer, DB, TSQL.Replace("?", DB.ToString().Trim()), Retries, ref oErrorString, ref oLocker);

                Thread oItem = new Thread(Executer.Process);
                oItem.Name = "ExecuteSQL " + DB.ToString().Trim();
                oItem.Start();
                oThread.Add(oItem);

            SqlContext.Pipe.Send(DateTime.Now.ToLongTimeString() +
            " : Start : " + oItem.Name.Replace("ExecuteSQL ", ""));
            Thread.Sleep(msDelay);

                while (RunningThreads(ref oThread, ref sStopped) >= MaxDOP)
                {
                    Thread.Sleep(1000);
                }
                iCurrentThread++;
            }

            // Wait for all Threads to Stop
            while (RunningThreads(ref oThread, ref sStopped) > 0)
            {
                Thread.Sleep(1000);
            }
            SqlContext.Pipe.Send("All Thread have Stopped with " +
            oErrorString.Count.ToString() + " Error/s ");
         
            if (oErrorString.Count > 0)
            {
            try
            {
                foreach (string sIndividualErrors in oErrorString)
                {
                    SqlContext.Pipe.Send(sIndividualErrors.ToString());
                }
            }
            catch (Exception ex)
            {
                ex.ToString();

            }

                throw new Exception("Error Occurred.");
            }

            return 0 - oErrorString.Count;
        }

        public static int RunningThreads(ref List<Thread> oThread, ref StringCollection oStops)
        {
            int iRunningCount = 0;

            foreach (Thread oIndividualThread in oThread)
            {
                if (oIndividualThread.IsAlive)
                {
                    iRunningCount += 1;
                }
                else if (!oStops.Contains(oIndividualThread.Name))
                {
                    oStops.Add(oIndividualThread.Name);
                   SqlContext.Pipe.Send(DateTime.Now.ToLongTimeString() + " : Stop  :  " + oIndividualThread.Name.Replace("ExecuteSQL ", ""));


                }
            }
            return iRunningCount;
        }
    }
class ExecuteSQL
    {

        private List<string> oExecuteErrors;
        private object oExecuteLocker;
        private string sExecuteServer;
        private string sExecuteDB;
        private string sExecuteTSQL;
        private int iExecuteRetries;

        public ExecuteSQL(string sServer, string sDB, string sTSQL,
        int iRetries, ref List<string> oErrors, ref object oLocker)
        {
            this.sExecuteServer = sServer;
            this.sExecuteDB = sDB;
            this.sExecuteTSQL = sTSQL;
            this.iExecuteRetries = iRetries;
            this.oExecuteErrors = oErrors;
            this.oExecuteLocker = oLocker;
        }

        public void Process()
        {
            int iTries = 1;
            SqlConnection oConn = new SqlConnection();

        Retry:
            oConn = new SqlConnection("Data Source=" + sExecuteServer +
            ";Initial Catalog=" + sExecuteDB + ";Integrated Security=SSPI;");
            try
            {
                oConn.Open();

                if (oConn.State == ConnectionState.Open)
                {
                    SqlCommand oCmd = oConn.CreateCommand();
                    oCmd.CommandText = sExecuteTSQL;
                    oCmd.CommandTimeout = 0;
                    oCmd.ExecuteNonQuery();

                    oCmd.Dispose();
                    oConn.Close();
                    oConn.Dispose();
                }
                else
                {
                    throw new Exception("SQL Server not Found or Unable to Connect to SQL Server");
                }
            }
            catch (Exception ex)
            {
                if (oConn.State != ConnectionState.Closed) oConn.Close();
                oConn.Dispose();

                if (iTries <= iExecuteRetries)
                {
                    Thread.Sleep(5000);
                    iTries += 1;
                    goto Retry;
                }
                else
                {
                    lock (oExecuteLocker)
                    {
                        char cSpace = char.Parse(" ");
                        oExecuteErrors.Add(this.sExecuteDB.PadRight(16, cSpace) + " : " + ex.Message);
                    }
                }
            }
        }

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