>Also, the interesting thing about that situation is that there is no use of a datareader in the flow of logic. In fact, I only use a datareader in a GetSchema() method but that one is not called from the SQLExec() method. Basically, the stack trace gives this:
>
>

>at System.Data.SqlClient.SqlInternalConnectionTds.ValidateConnectionForExecute(SqlCommand command)
>   at System.Data.SqlClient.SqlConnection.ValidateConnectionForExecute(String method, SqlCommand command)
>   at System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async)
>   at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
>   at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
>   at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)
>   at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
>   at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
>   at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
>   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
>   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet)
>   at Framework.Framework.Data.SQLExec(String tcSQL)
>

>
>So, we can see this is in the DbDataAdapter.Fill() method. So, I have no idea why the datareader was mentioned in that error.

In this stack you have several RunExecuteReader and ExecuteReader and ExecuteDbDataReader.