I've got my Foreach Loop Container in PROD and it is doing what it is supposed to do so this is really just a learning experience.
I put this in TEST: I have at the start a Script Task with the code below (which is failing Error: "The element cannot be found in a collection. This error happens when you try to retrieve an element from a collection on a container during execution of the package and the element is not there."), 3 variables (TrainingFilePresent(set default to 1), TrainingFilePath (set to C:\Users\wally\desktop\Training\), TrainingFileName (set to Training.csv), 2 Sequence Containers (one for constraint Success (load Training File), one for constraint Failure (Load Alt File)).
public void Main()
String filepath = Dts.Variables["user::TrainingFilePath"].Value.ToString() + Dts.Variables["user::TrainingFileName"].Value.ToString();
Dts.TaskResult = (int)ScriptResults.Success;
Dts.TaskResult = (int)ScriptResults.Failure;