Object Ref Error Inside AutomaticUpdater ControlAnswered

I started getting this error while trying to get an update:

[ERROR - 2023-07-28 15:08:43] - Exception: System.Exception: Update: Update failed. Unable to check for updates, the server file failed to load. / Error trying to save file: Error downloading "https://cloudradialdv.blob.core.windows.net/testcontainer/updates/wyserver.wys": The remote server returned an error: (400) Bad Request.

The issue is odd because that file is publically accessible and has been working in the past.

If I go into the debugger I can see an object ref exception happening on this call stack:

AutomaticUpdater.dll!wyDay.Controls.PipeClient.SendMessage(byte[] message)
AutomaticUpdater.dll!wyDay.Controls.UpdateHelper.RetrySend(byte[] message)
AutomaticUpdater.dll!wyDay.Controls.UpdateHelper.bw_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)

Code that sets up the updater:

                var auBackend = new AutomaticUpdaterBackend
                {
                    GUID = "e13a50ed-983b-4075-a6a5-9b6dd3f8f13c",
                    UpdateType = UpdateType.Automatic,
                    ServiceName = this.agentContext.ServiceName
                };

                auBackend.UpdateSuccessful += (s, e) => LoggingService.Info($"Update: Update succesesful.");
                auBackend.CheckingFailed += (s, e) => LoggingService.Error($"Update: Update failed. {e.ErrorTitle} / {e.ErrorMessage}"); ;
                auBackend.UpToDate += (s, e) => LoggingService.Info($"Update: Program is up-to-date.");
                auBackend.ReadyToBeInstalled += (s, e) =>
                {
                    if (auBackend.UpdateStepOn == UpdateStepOn.UpdateReadyToInstall)
                    {
                        LoggingService.Info($"Update: Preparing installation...");
                        auBackend.InstallNow();
                    }
                };

                auBackend.Initialize();
                auBackend.AppLoaded();

                auBackend.ForceCheckForUpdate();