Ladybug tools Installation Issue

This is my first time using Rhino/Grasshopper/Ladybug package. (I’m using Rhino7 and Ladybug Tools 1.2.0 )
All went well until I followed the instructions to install Ladybug and got the following error message when I set the first component to True:

Runtime Error (Python Exception): Download failed with the error:
an exception occurred during a WebClient request.
line 67, in download_file_by_name, “”
line 127, in script

I would appreciate your kind guidance!

Hi @ImKet ,

The message says that you already have an installation in that folder.
Do you still get the error after you delete the folder at C:\Users[USERNAME]\ladybug_tools ?

If so, it’s likely an issue with a firewall on your machine. If it’s a firewall that’s controlled by an IT department and that you don’t control, we highly recommend purchasing a single-click installer for this case since it will save a lot of time going back and forth to add firewall exceptions for all of the different software dependencies. You can get info on the single-click installer by emailing

Update in 2023: Try using the Pollination Grasshopper installer. It is free and comes with all the Ladybug Tools core libraries. It also installs Radiance, and OpenStudio.