Grasshopper DataTree Object not Reading Properly

Hi guys, I was playing around with Ladybug and encountered this strange issue. When Rhino is launched without admin rights, DataTree object output from python code appears and “tree{…}” instead of the normal Data Tree we usually see in Grasshopper. Tooltip from Grasshopper says it’s “One locally defined value”. Please see screenshot below.

This only appeared recently, everything was working in December 2019. This issue disappears if Rhino is launched with admin right. Has anyone encountered this, or have any idea on how to resolve it? I have tried reinstalling Rhino but that didn’t help

What’s up guys… Nobody is answering a couple of questions I posted. Just wanna report back, in case anyone faces this issue in the future, I have a workaround.

I have modified the ladybug script to change the output from datatree to a normal nested list in ironpython. Of course, that will give us “Ironpython Runtime List” as outputs. then, create a C# component that does “Output = input”, or “A = x”, item access. Feed “Ironpython Runtime List” into that C# component, and that will do the trick.

Hi - Thanks for adding your workaround!
Can you reproduce the issue with factory-default Grasshopper components or does this only happen with the Ladybug components? If this is something that is strictly related to Ladybug, you might want to inform the developers over at

Hi wim! It’s happening to all GHpython node that is outputting data in DataTree object type. I suspect it has to do with installation, but reinstalling Rhino didn’t help. This error only appeared this year, everything was fine in Dec 2019

Hi - I’m not seeing that here so far:

Just to clarify, with “launching without admin rights”, you mean that you are not using the Run as administrator option when you right-click on a Rhino icon, correct?

Yep, that’s what I mean by “launching without admin rights”.

I have the exact same experience, things works perfectly fine on my personal computer with or without admin rights. The issue only shows up on my work laptop. I am trying to get my office IT to check if it has anything to do with their group policies. I’ll report back if we could find the cause