"Unhandeld Exception" when I run script


I’m trying to write the parameters “Panel” en “Ciruit number” in 2 other project parameters in Revit. Also I want Dynamo to check if the parameters “Panel” and “Circuit number” are emty. If so, then the parameters don’t have to change.

Last week it was just working fine, but when I tried it today it gave an error “Unhandled Exception”. See the script below:

Anybody knows what I am doing wrong here?

Thanks in advance.

Now with a good screenshot.

is there a need here to compose any function or sort? i dont think so, you can just get its parameter and set it accordigly.

Yes, there is. I want to sort out all the elements which do not have a value. And then only want to set these parameters.

why not just use HasValue node instead?