SQL error: A severe error occurred on the current command. The results, if any, should be discarded

I am using VS Studio 2105 to create a console app and SSMS 2014 v 12.0.410. I am running a VB.Net console app that does polling on the 0 and 30 second mark. It will do this 24 by 7. As part of the process, a background thread is spawned. (See explanation below).The database connection string is: add key="ConnectionString" value="Server=xxxxx,14334;Database=xxx_dev;Uid=xxx_dev;Password=xxxxxx;MultipleActiveResultSets=true"The class and its functions called for the open and closing of the database: Dim strConnectionString As String = ConfigurationManager.AppSettings("ConnectionString") Sub OpenDB() If objConn.State = Data.ConnectionState.Open Then objConn.Close() End If objConn.ConnectionString = strConnectionString objConn.Open() objCmd.Connection = objConn objCmd.CommandType = Data.CommandType.Text End Sub Sub CloseDB() objConn.Close() End SubI customized the error message to get all that I could about it.>A severe error occurred on the current command. The results, if any, should be discarded. --> State: 0 --> Source: .Net SqlClient Data Provider --> Error number: 0 --> Line number: 0 --> Line number: -2146232060 --> Class: 11 --> Procedure: --> Call stack: at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action\`1 wrapCloseInAction) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action\`1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString, Boolean isInternal, Boolean forDescribeParameterEncryption) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, Boolean inRetry, SqlDataReader ds, Boolean describeParameterEncryptionRequest) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource\`1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at ReliableSiteBandwidthPollingTester.Module1.SaveBandwidthPollingLog(Switch SaveSwitch, String& strMessage) in C:\Dans\Work 2\Working Area\Switch Polling - design 3\Tester apps\ReliableSiteBandwidthPollingTester\ReliableSiteBandwidthPollingTester\Module1.vb:line 427The polling process: It interrogates a network switch gathering data. After the interrogation, it then executes a simple stored procedure 105 times which inserts a row into a table each time. It then starts a background thread which executes a "calculation process" stored procedure that uses the table just inserted into as well as other tables. It does inserts into another table - and potentially deletes. A transaction is used. It either commits or rolls back. However, I believe that the procedure does not finish before the next poll begins - the next 30 second mark.The simple insert stored procedure has been tested stand-alone many times and works fine every time.The more complicated "calculation process" stored procedure has been tested stand-alone many times and works fine every time.I start the console app and it it polls 3 times and the fails with that error. Before failing, it writes the out 3 sets of 105 rows to the table. It also inserts 290 rows into another table as part of the process. Sub PollSwitch(sender As Object, e As ElapsedEventArgs) Dim strMessage As String = "" Dim strPollError As String = "" Dim bPollResult As Boolean Dim NetworkSwitch As Switch ' This is the format to display as it is how it is stored in the info log table. Dim dtFormat As String = "yyyy-MM-dd hh:mm:ss.fff" If bErrorInThread = True Then ' There was an error in the background thread during the previous issuance of the thread. So do not continue. strMessage = "Critical Error - in the background thread. See the 'BandwidthInfoLog' table. Refer to this log date: " + dtThreadStartDateTime.ToString(dtFormat) End If If strMessage = "" Then ' Create a new instance. NetworkSwitch = New Switch(strCommandLineSwitchIP, strCommandLineCommunityString) Try ' Do the switch polling. bPollResult = NetworkSwitch.Poll(strPollError) If bPollResult = False Then strMessage = "Warning - in bandwidth poll. Poll error at " & Now & ": " & strPollError & " Poll will continue." Else ' Save to the bandwidth polling log. SaveBandwidthPollingLog(NetworkSwitch, strMessage) If InStr(strMessage, "Critical") = 0 Then Console.WriteLine("Successfully polled at " & Now() & ".") ' Set the date/time as it will be used above in an error message should the thread process fail. dtThreadStartDateTime = Now() '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Now do the "calculation process" - it will be in it's own background thread. ' Note: the thread ends when the ProcessCalculatedSwitchPolling method ends. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' Dim thread As New Thread(AddressOf ProcessCalculatedSwitchPolling) thread.Start() End If End If Catch ex As Exception strMessage = "Critical Error - in bandwidth poll - " & ex.Message & "Switch: " & strCommandLineSwitchIP End Try End If If InStr(strMessage, "Critical") > 0 Then ' Stop this method (this poll timer) as there is a critical error. DisposeTimer() ' Show message. Console.WriteLine(strMessage) Console.WriteLine("--------->>>> PRESS ENTER TO QUIT.") Console.ReadKey() ' Exit the console application here as there is a critical error. ' Normally the exit would occur in the main method when the User hits a key. Environment.Exit(0) End If End SubThe call stack shows it fails on line 427 which is the .ExecuteNonQuery() line. Sub SaveBandwidthPollingLog(ByVal SaveSwitch As Switch, ByRef strMessage As String) Const strFunctionId As String = "VB - savebandwidthpollinglog. Error ID: " Const iSQLErrorId As Integer = 501 Const iCATCHErrorId As Integer = 502 Dim dtCurrentDateTime As Date = Now() Dim strProcessInfoLogResult As String = "" Dim strAdditionalInfoForLog As String = "" ' This is the format to display as it is how it is stored in the info log table. Dim dtFormat As String = "yyyy-MM-dd hh:mm:ss.fff" DBFunc.OpenDB() Try With DBFunc.objCmd .CommandType = Data.CommandType.StoredProcedure .CommandText = "InsertBandwidthLogTest6" ' Note: it was timing out, so the SqlCommand.CommandTimeout property has expired; the default timeout is 30 seconds. .CommandTimeout = 0 For Each SavePort In SaveSwitch.Port .Parameters.Clear() .Parameters.AddWithValue("@SwitchIP", SaveSwitch.IP) .Parameters.AddWithValue("@PortIndex", SavePort.Index) .Parameters.AddWithValue("@PortSpeed", SavePort.Speed) .Parameters.AddWithValue("@InOctets", SavePort.InOctets) .Parameters.AddWithValue("@OutOctets", SavePort.OutOctets) .Parameters.AddWithValue("@TimeStamp", SavePort.TimeStamp) .ExecuteNonQuery() Next End With Catch sqlex As SqlException ' Its a critical issue. If InStr(sqlex.Message, "Critical") > 0 Then ' Coming from the stored procedure. strMessage = sqlex.Message Else strProcessInfoLogResult = ProcessInfoLog(dtCurrentDateTime, sqlex.Message + " --> State: " + sqlex.State.ToString() + " --> Source: " + sqlex.Source + " --> Error number: " + sqlex.Number.ToString() + " --> Line number: " + sqlex.LineNumber.ToString() + " --> Line number: " + sqlex.HResult.ToString() + " --> Class: " + sqlex.Class.ToString() + " --> Procedure: " + sqlex.Procedure + " --> Call stack: " + sqlex.StackTrace, strAdditionalInfoForLog, strFunctionId, iSQLErrorId) End If Catch ex As Exception strProcessInfoLogResult = ProcessInfoLog(dtCurrentDateTime, ex.Message, strAdditionalInfoForLog, strFunctionId, iCATCHErrorId) Finally ' Close database. DBFunc.CloseDB() End Try End SubThe Thread process: Public Sub ProcessCalculatedSwitchPolling() Const strFunctionId As String = "VB - processcalculatedswitchpolling. Error ID: " Const iSQLErrorId As Integer = 601 Const iCATCHErrorId As Integer = 602 Dim strProcessInfoLogResult As String = "" Dim strAdditionalInfoForLog As String = "" Dim strInputParms As String = "" ' Set for the error log. strInputParms = "S/P parmameters - switch IP Address: " & strCommandLineSwitchIP DBFunc.OpenDB() Try With DBFunc.objCmd .CommandType = Data.CommandType.StoredProcedure .CommandText = "ProcessBandwidthLogCalculatedTest6" ' Note: it was timing out, so the SqlCommand.CommandTimeout property has expired; the default timeout is 30 seconds. .CommandTimeout = 0 .Parameters.Clear() .Parameters.AddWithValue("@SwitchIP", strCommandLineSwitchIP) .ExecuteNonQuery() End With Catch sqlex As SqlException ' Its a critical issue. If InStr(sqlex.Message, "Critical") > 0 Then ' Coming from the stored procedure. ' Set the global variable - the thread error indicator. bErrorInThread = True Else ' Not coming from the stored procedure. bErrorInThread = True ' Log the exception as it was not logged in the stored procedure. strAdditionalInfoForLog = strInputParms strProcessInfoLogResult = ProcessInfoLog(dtThreadStartDateTime, sqlex.Message, strAdditionalInfoForLog, strFunctionId, iSQLErrorId) End If Catch ex As Exception bErrorInThread = True ' Log the exception. strAdditionalInfoForLog = strInputParms strProcessInfoLogResult = ProcessInfoLog(dtThreadStartDateTime, ex.Message, strAdditionalInfoForLog, strFunctionId, iCATCHErrorId) Finally ' Close database. DBFunc.CloseDB() End Try End Sub