NU3034 Warning with untrusted signer blocks the execution of my robot


I am trying to launch a robot that uses UiPath.UIAutomation.Activities : 19.11.1
On the machine on which I want to launch the robot, there is a firewall restriction that forbids the automatic download of packages from and

I hence installed manually the package in C:\ProgramFiles(x86)\UiPath\Studio\Packages, and all its dependencies:

  • “AvalonEdit”: “5.0.3”,
  • “Extended.Wpf.Toolkit”: “2.8.0”,
  • “Humanizer.Core”: “2.4.2”,
  • “Newtonsoft.Json”: “11.0.2”,
  • “UiPath”: “19.10.7312.25504”,
  • “UiPath.OCR.Contracts”: “2.2.1”,
  • “UiPath.Vision”: “2.0.0”

However, after launching the robot it crashes, because the screens couldn’t have been properly recognized.

I can see in the %userprofile%/.nuget/packages/my-robot/my-version/AllDependencies.json file the following log message:

The problem now concerns the package Extended.WPF.Toolkit.2.8.0 that I downloaded from: NuGet Gallery | Extended.Wpf.Toolkit 2.8.0

How can I do to work this around?
If this warning stays, the screen recognition won’t be properly made, and I won’t be able to execute my robot on my execution machine.

NB: The content of my NuGet.config file is:

Thanks for your help.