Good Day all, please bare with me I’m really new to Dynamo and have only been using it since monday for a varsity project. If anyone can help I would greatly appreciate it! So the issue is that I have to use excel to list functions in dynamo code to open and close louvers at certain time of the day. I have created the parametric family in revit and tested the opening and closing with a number slider which all works, but when I try to use the excel list, which is two columns “a time and a opening and closing ratio” i get this error from the get item at index node “Warning: List.GetItemAtIndex operation failed. Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index” So I think the solution is to get a node to read the two list components at the same time to produce the value needed for the opening and closing of the louvres. Sorry if this question is trivial and easy to get around, I am just at a loss at the moment on how to fix the problem and any help would be greatly appreciated. Thank you 
Try to drop the List.Create nodes, nesting goes up a level after that node.
Or try List@Level and set it to level 2
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Thank you so much for your help Marcel, I did what you said and no more errors!!! 
what option i gave you did it?
option 2 is the way to go i think