Tool.CreateAssembly not working



What am I doing wrong? I just get null.


I’ve even simplified things and used select model elements to feed in. Both directly to the node and with List.Map.


Hi @David3

It works as expected. which dynamo, Which Revit & Steam nodes package version your using?


Revit 2016

I tried Revit 2017 without any luck either.


@David3 Try this -> uninstall all the custom packages including steam nodes and then restart revit install only steam nodes packages. See if that helps!


@Kulkul that worked! with tool.createassembly am I able to create an assembly for each of the elements rather than a single assembly of all of the elements?


Nevermind. Using List.Map I was able to do what I was requesting. Thanks for the help. I’ll try to reinstall the other packages I uninstalled. What should I do if I install a package that conflicts with another?


@David3 That would be another topic of the day :slight_smile:


Hi David3,

If you want to create an assembly for each of the elements, check this workflow by @Dimitar_Venkov.

The “Transaction.End” node seems to do the job.

Kind regards,


@MJB-online Thanks Mark. That’s the post I stumbled upon earlier that I used!


Hi, Anybody know why the Tool.RenameAssembly from SteamNodes package retrive always a null? Reinstalling a packages seems not work here. I have no more packages installed.

I use Revit 2017, Dynamo, SteamNodes 1.2.4.

I am looking for way to change the name of assembly created by dynamo.



Hi @nieuchron,

I think these additional nodes will solve your problem.

Kind regards,


Thanks, It’s works for me. Can you explain logic behind it?