Exception from Visual Studio Extension Gallery Service

I'm trying to make my extension automatically update itself when new versions are pushed to the Visual Studio Gallery. There are a few guides on how one may achieve this, but they are a couple years old and may not apply.

I'm trying to query the IVsExtensionRepository as follows:

var _extensionRepository = (IVsExtensionRepository)Microsoft.VisualStudio.Shell.Package.GetGlobalService(typeof(SVsExtensionRepository));
var query = _extensionRepository.CreateQuery<VSGalleryEntry>(false, true)
                .OrderByDescending(n => n.Ranking)
                .Skip(0)
                .Take(25) as IVsExtensionRepositoryQuery<VSGalleryEntry>;

query.ExecuteCompleted += Query_ExecuteCompleted;
query.ExecuteAsync();

At Query_ExecuteCompleted I'm receiving an exception from the server: The remote server returned an error: (400) Bad Request.

A stack trace is provided:

Server stack trace: 

at System.Runtime.AsyncResult.End[TAsyncResult](IAsyncResult result)
   at System.ServiceModel.Channels.ServiceChannel.SendAsyncResult.End(SendAsyncResult result)
   at System.ServiceModel.Channels.ServiceChannel.EndCall(String action, Object[] outs, IAsyncResult result)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeEndService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]: 

The service is hosted at: https://visualstudiogallery.msdn.microsoft.com/services/dev12/extension.svc

Does anyone know how I can use this service? Either through the IVsExtensionRepository or manually?