Thanks ! I have different error when I launch the same package UiPath Studio 21.0 in another machine with a different network setup (403 browser blocked) and for the other version 20.0.2 there is no such error, Could you please suggest here whether this is also related to the proxy configuration
You are able to access the nuget from your browser. I think the issue is connecting from uipath feed. Could you pls go to %appdata% and nuget folder and inside the folder you could find nuget.config delete this file and restart your studio and try. If you still unable to get the nuget package we have to modify the nuget.config with your proxy details. The issue you are currently facing due to proxy only.
Please try the above steps and let us know. Thanks.