Sequence execution all containing similar dataflows to database results in 1 sequence getting errors, all have TransactionOption=Supported

Question

I have 3 sequence Containers, all with TransactionOption = Supported. Each individual Sequence container contains a dataflow task that executes a script component to get data and write to output fields in table using OLE DB table Destination.
All three Script Component sets up the data for the tables and has a preexecute, here is part of code in script component
   private System.String[] Transmissions;
    /// <summary>
    /// This method is called once, before rows begin to be processed in the data flow.
    /// You can remove this method if you don't need to do anything here.
    /// </summary>
    public override void PreExecute()
        base.PreExecute();
         * Add your code here
        this.Transmissions = this.ReadOnlyVariables["User::TransmissionData"].Value as System.String[];
    public override void CreateNewOutputRows()
          Add rows by calling the AddRow method on the member variable named "<Output Name>Buffer".
          For example, call MyOutputBuffer.AddRow() if your output was named "MyOutput".
        foreach (System.String Row in Transmissions)
            try
                System.Array ar = Row.Split(",".ToCharArray());
                //System.Int32.Parse(ar.GetValue(0).ToString());
                //System.DateTime.Parse(ar.GetValue(1).ToString());
                //System.Decimal.Parse(ar.GetValue(2).ToString());
                System.DateTime.Parse(ar.GetValue(0).ToString());
                System.DateTime.Parse(ar.GetValue(1).ToString());
                System.Int32.Parse(ar.GetValue(3).ToString());
                float.Parse(ar.GetValue(6).ToString());
                OutputBuffer.AddRow();
                OutputBuffer.StartDatetime = System.DateTime.Parse(ar.GetValue(0).ToString());
                OutputBuffer.EndDateTime = System.DateTime.Parse(ar.GetValue(1).ToString());
When I just execute the first two sequence containers, everything works, data written to tables.
When I include the third sequence container, it throw an error like
Script Component has encountered an exception in user code:
Project name:  SC_2c..........................
Object reference not set to an instance of object.
at ScriptMain.PreExecute()
at
Microsoft.SqlSever.Dts.Piperline.ScriptComponentHost.PreExecute()
Any ideas why when I include the third sequence/Script Component it fails? It looks like it failing in PreExecute
thanks in advance.
Greg Hanson

Answer 1

HI Arthur thanks for answer, yes i believe it is a timing issue because when I run each container individually it works. I need to keep each sequence container separate, I believe, since a Script task (in C#) that parses the text file feeds each container
separately. Each Sequence Container has "Transaction Supported" set. If I include 1 & 3, 2 & 3 it FAILS.
This  is rough schematic of what I have. I thought of connecting the sequence containers, but that won't work as my Script Task that parses the file feeds separate into each sequence container:
Script Task - Parses file into 3 separate DTS variables all containing array of strings:
Transmission array of strings
Energy array of strings
Tag array of strings
Script Task feeds into 3 separate Containers:
Transmission container containing dataflow task that has Script Component that converts array to rows that uses oledb dest to load data into  transmission table
Energy container containing separate dataflow task  that has Script Component  that converts array to rows that uses oledb dest to load data into Energy table
Tag container containing separate dataflow task  that has Script Component that converts array to rows that uses oledb dest to load data into Tag table **** THIS FAILS
I have also just tried using 1 sequence container for all Data Flow tasks, and it still fails on the last Load to Tag table data flow getting
Script component has encountered an exception in user code:
Project name:   SC_...
Object reference not set to an instance of object.
at ScriptMain.PreExecute()
at
Microsoft.SqlServer.Dts.Pipeline.ScriptComponentHost.PreExecute()
YET WHEN I EXECUTE THIS CONTAINER SEPARATE IT WORKS.
When I set a breakpoint in preexecute in LoadDatainto Tag Table Script Component and hit break, it WORKS!
Please help this is due tomorrow! 
Greg Hanson