Changing Type Parameters from Filtered list of Windows

Hello Everyone.
What I’m trying to do is :

  1. Filter my window types to only those whose “Type Mark” contains the “WN-” String. This part seems to work, I get a list that once is Flatten it shows me the types that comply whit that.
  2. The next step is to change the value of the Type parameter called “Design U-Factor” - This parameter is made as Type parameter using a shared parameter.

But once I connect the string node to the value of the Element.SetParameterByName node I get this

Warning: Internal error, please report: Dereferencing a non-pointer.

Here is an image of what I’m doing.

Any thoughts??

Thanks in advanced for helping a Newbie


You are plugging in a string to the parameter value, perhaps the parameter value is a number?

Hope that helps,


Hey Mark.
Thanks for the help. I just changed the string node to a number node and the result is the same.

Sorry I’m away from my PC or I would make the graph, apologies, I’ll do it tomorrow if we can’t figure it out now.

The node is Element Set Parameter. Rather than getting the Family Types, get all elements of the category, filter by their type then set parameter.

Hope that’s useful…


Hi @sernaferrer,

Try the two steps below:
Disconnect “Element.GetParameterValueByName” and “List.FilterByBoolmask”.
Connect “Family.Types” and “List.FilterByBoolmask”.
In your graph you are filtering the strings, not the family types.

Kind regards,

Hey Mark.
I think I did what you suggested and it seemed to work.

Just let me recap, to actually check if I understood the issue. In your solution My first action is to actually assign the values to the “Design U Value” Type parameter and then to proceed with the filtering by Type Mark


I also did what you suggested

It was a great solution. I finally understood that List.FilerByBoolMask, should feed not from my String obtained from my parameters name but from my actual Family Types.

1 Like

Thanks for the help guys , you are awesome!