Why does the setup show "certificate error" and recommend not installing? That causes one to question whether they might cause problems within installed programs.
Windows' certification system always checks if any installed application is certified by Microsoft and if it's not - it returns this error. Although our plugin isn't certified by Microsoft, I can assure you that it's perfectly safe to install it and it doesn't contain any spyware or malware.
It's been build with Microsoft's official tools (Visual Studio + .NET Framework).