One concept that you need to watch out for is making sure that the variables defined inside both of your containers need to have the same names. So if your Parameter container had a numeric variable called "Temp", then your FileGlobals container would need a numeric variable called "Temp". The naming conventions need to be the same as well as the data type. The order of the variables inside the cluster doesn't matter. If you don't use the same names for the variables, you will receive the error you mentioned. Attached is a short snippet of code that shows you how to correctly assign containers.
Hope this helps!