Deploy Error: An Lockdown error occurred. The error code was "MuxError"

Question

I get the above error but it means nothing to me other than that there was a problem with the deploy.
I did a search but found nothing similar.

What does that message mean and how can I fix it?

This is a Xamarin Forms app being deployed on an iPad Air (4th gen) running iOS 14.8.1. I'm developing using VS 2019 v 16.11.5

Thanks!

Answer 1

@Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) I am seeing the same thing. I am attempting to deploy a brand new Xamarin Forms iOS project with 0 changes, on the latest version of VS 2019 (16.11.9). Here is the detailed error message:

   Xamarin.Messaging.Exceptions.MessagingRemoteException: An error occurred on client IDBLocal while executing a reply for topic xvs/idb/deploy-app ---> iMobileDevice.Lockdown.LockdownException: An Lockdown error occurred. The error code was MuxError  
      at iMobileDevice.Lockdown.LockdownErrorExtensions.ThrowOnError(LockdownError value) in D:\a\1\s\imobiledevice-net\Lockdown\LockdownErrorExtensions.cs:line 34  
      at Xamarin.iOS.Windows.AppleService`1.Start() in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\AppleService.cs:line 42  
      at Xamarin.iOS.Windows.Installer.ApplicationSession.<>c__DisplayClass21_0.<GetApplicationProperties>b__0() in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\Installer\ApplicationSession.cs:line 180  
      at Xamarin.iOS.Windows.AppleDeviceExtensions.ExecuteWithSession[T](AppleDevice nativeDevice, Func`1 action) in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\Extensions\AppleDeviceExtensions.cs:line 42  
      at Xamarin.iOS.Windows.Installer.ApplicationSession.GetApplicationProperties(String appBundleId) in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\Installer\ApplicationSession.cs:line 176  
      at Xamarin.iOS.Windows.Installer.ApplicationSession.IsAppInstalled(String appBundleId) in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\Installer\ApplicationSession.cs:line 152  
      at Xamarin.iOS.Windows.Installer.ApplicationSession.Deploy(String appRootFolder, String appBundleId, String appName) in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\Installer\ApplicationSession.cs:line 83  
      at Xamarin.iOS.Windows.HotRestartClient.Deploy(AppleDevice nativeDevice, String appBundleId, String appBundleName, Boolean& incremental) in C:\a\1\s\src\Tools\Xamarin.iOS.Windows.Client\HotRestartClient.cs:line 249  
      at Xamarin.Messaging.IDB.Local.DeployAppMessageHandler.<ExecuteAsync>d__5.MoveNext() in D:\a\_work\1\s\src\Messaging\Xamarin.Messaging.IDB.Local\Handlers\DeployAppMessageHandler.cs:line 40  
   \--- End of stack trace from previous location where exception was thrown ---  
      at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()  
      at Xamarin.Messaging.IDB.Local.DeployAppMessageHandler.<ExecuteAsync>d__5.MoveNext() in D:\a\_work\1\s\src\Messaging\Xamarin.Messaging.IDB.Local\Handlers\DeployAppMessageHandler.cs:line 56  
   \--- End of stack trace from previous location where exception was thrown ---  
      at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()  
      at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)  
      at Xamarin.Messaging.Client.RequestHandler`2.<HandleAsync>d__5.MoveNext() in D:\a\_work\1\s\src\Xamarin.Messaging.Client\Handlers\RequestHandler.cs:line 0  
   \--- End of stack trace from previous location where exception was thrown ---  
      at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()  
      at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)  
      at Xamarin.Messaging.Client.MessageHandlerManager.<>c__DisplayClass16_1`2.<<RegisterHandlerAsync>b__2>d.MoveNext() in D:\a\_work\1\s\src\Xamarin.Messaging.Client\MessageHandlerManager.cs:line 0  
   \--- End of stack trace from previous location where exception was thrown ---  
      at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()  
      at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)  
      at Xamarin.Messaging.Client.MessagingClient.<ReplyAsync>d__32`2.MoveNext() in D:\a\_work\1\s\src\Xamarin.Messaging.Client\MessagingClient.cs:line 0  
      --- End of inner exception stack trace ---  
      at Xamarin.Messaging.Client.ApplicationMessageExtensions.<>c__DisplayClass10_0`1.<OfResponse>b__1(MqttApplicationMessage m) in D:\a\_work\1\s\src\Xamarin.Messaging.Client\Extensions\ApplicationMessageExtensions.cs:line 189  
      at System.Reactive.Linq.ObservableImpl.Select`2.Selector._.OnNext(TSource value) in d:\a\1\s\Rx.NET\Source\src\System.Reactive\Linq\Observable\Select.cs:line 39  
   \--- End of stack trace from previous location where exception was thrown ---  
      at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()  
      at Xamarin.Messaging.Client.MessagingClient.<PostAsync>d__21`2.MoveNext() in D:\a\_work\1\s\src\Xamarin.Messaging.Client\MessagingClient.cs:line 190: 01/30/2022 01:09:09Z  
       DateTime=2022-01-30T01:09:09.5413804Z: 01/30/2022 01:09:09Z  

[Edit] Upgrading to VS 2022 fixed the issue.

Answer 2

For the record, I got this error out of the blue and was about to put my fist through my screen.
I re-seated the USB cable and the problem went away.

Answer 3

I'm running into this same issue with one of my xamarin apps, but not others. I have tried reseating the USB cable on multiple ports and multiple cables with no luck. I'm running latest versions of visual studio, xamarin package and itunes.