Hi I know I’m missing something here.
I’m trying to get the Assembly code from Windows in an assembly to copy into the assembly code of the assembly they are made into.
I’ve attached were I got to.
Thank you so much.
It looks like that Assembly.Members node is intended for use with an actual Revit Assembly. Instead, pass the output from All Elements of Category straight into your Element.Type node. Then you can retrieve the Assembly Code (which is a type parameter) and write it to the elements themselves. I don’t have access to Revit so I can’t do this myself, but hopefully the image below provides some clarity.
This also assumes that you have an instance parameter called Assembly Code as well.
Hi
The problem is i’m trying to copy the Assembly code from the Window into the Assembly the window is part of. I have 3 windows made into an assembly for example which already have the assembly code WT-03. However when I tag the Assembly the Assembly Code is blank.
I want the Assembly to take the Assembly Code from its members.
Not sure if this is possible. 
I see, so you’re actually referring to a Revit assembly. In that case, instead of getting all elements from the “Windows” category, you should set it to “Assemblies”. You may have to do some additional filtering if you have other assemblies which don’t have any windows, but that should be a good starting point.