_support's throwInvalidParameter(a reference to item i of theList, "", number, "List item is wrong type: " & eText) -- note: AS doesn't provide a meaningful reference when `repeat with aRef in  listObject's _list_` is used (e.g. `item 2 of _list_`), so to provide useful error messages a counting loop is used and a readable reference constructed using that (e.g. `item 2 of {3, "x"}`)