Unity Exception when attempting to import a Google Spreadsheet:

  WebException: Error writing request: The authentication or decryption has failed.
  System.Net.WebConnectionStream.WriteHeaders ()
  System.Net.WebConnectionStream.SetHeaders (System.Byte[] buffer) (wrapper remoting-invoke-with-check) 
  System.Net.WebConnectionStream:SetHeaders (byte[])
  System.Net.HttpWebRequest.SendRequestHeaders (Boolean propagate_error)
    Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
  System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, 
  System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
    (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/
         mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
  System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) 
    (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/
         mcs/class/corlib/System.Reflection/MethodBase.cs:115)
  UnityEditor.HostView.Invoke (System.String methodName, System.Object obj) 
    (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/GUI/DockArea.cs:244)
  UnityEditor.HostView.Invoke (System.String methodName) 
    (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/GUI/DockArea.cs:237)
  UnityEditor.HostView.OnGUI () 
    (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/GUI/DockArea.cs:129)

This was an issue with Google Authentication. It was fixed in GDE Version 2.0.1. Update to the latest GDE to fix resolve this exception.