[13.3.5+70b] Can't use "aspire add" at all

[tebeco]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

aspire add(or without-l Debug`)

error:

❌ Unable to stop one or more running Aspire AppHost instances. Please stop the application and try again.

Unsure if related I have more Windows Defender popup

Expected Behavior

Should not fail to "Open a Socket" connection when adding integration

Steps To Reproduce

pre-requisite:

• have the dotnet Aspire with blazor web

(i did a reboot)

repro:

• start PC
• open nothing expect terminal
• type in aspire add -l Debug (or without -l Debug)

error:

❌ Unable to stop one or more running Aspire AppHost instances. Please stop the application and try again.

detail:

Select an integration to add:

  azure-kubernetes (Aspire.Hosting.Azure.Kubernetes)
  azure-kusto (Aspire.Hosting.Azure.Kusto)
  azure-network (Aspire.Hosting.Azure.Network)
  azure-operationalinsights (Aspire.Hosting.Azure.OperationalInsights)
  azure-postgresql (Aspire.Hosting.Azure.PostgreSQL)
> azure-redis (Aspire.Hosting.Azure.Redis)
  azure-search (Aspire.Hosting.Azure.Search)
  azure-servicebus (Aspire.Hosting.Azure.ServiceBus)
  azure-signalr (Aspire.Hosting.Azure.SignalR)
  azure-sql (Aspire.Hosting.Azure.Sql)

[09:40:38] [info] Stdout: Selection result: [bold]redis[/] (Aspire.Hosting.Redis)
[09:40:38] [dbug] DotNetAppHostProject: Connecting to auxiliary backchannel at C:\Users\ahert\.aspire\cli\backchannels\auxi.sock.089bb54eedf6ef7a.f097cb44f00e.32476
[09:40:38] [warn] DotNetAppHostProject: Failed to stop running instance System.Net.Sockets.SocketException (10061): No connection could be made because the target machine actively refused it.
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.CreateException(SocketError, Boolean) + 0x66
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ConnectAsync(Socket, CancellationToken) + 0xc4
   at Aspire.Cli.Backchannel.AppHostAuxiliaryBackchannel.<CreateFromSocketAsync>d__30.MoveNext() + 0x2ac
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine&) + 0x61
   at Aspire.Cli.Backchannel.AppHostAuxiliaryBackchannel.CreateFromSocketAsync(String, String, Boolean, Socket, ILogger, CancellationToken) + 0x7f
   at Aspire.Cli.Projects.RunningInstanceManager.<StopRunningInstanceAsync>d__6.MoveNext() + 0x123
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine&) + 0x61
   at Aspire.Cli.Projects.RunningInstanceManager.StopRunningInstanceAsync(String, CancellationToken) + 0x48
   at System.Linq.Enumerable.SizeOptIListSelectIterator`2.MoveNext() + 0x73
   at System.Threading.Tasks.Task.WhenAll[TResult](IEnumerable`1) + 0x8a
   at Aspire.Cli.Projects.DotNetAppHostProject.<FindAndStopRunningInstanceAsync>d__41.MoveNext() + 0x142
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine&) + 0x61
   at Aspire.Cli.Projects.DotNetAppHostProject.FindAndStopRunningInstanceAsync(FileInfo, DirectoryInfo, CancellationToken) + 0x43
   at Aspire.Cli.Commands.AddCommand.<ExecuteAsync>d__13.MoveNext() + 0x1148
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x5f
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x93
   at Aspire.Cli.Commands.AddCommand.<GetPackageByInteractiveFlowWithNoMatchesMessage>d__16.MoveNext() + 0x19a
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x72
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x93
   at Aspire.Cli.Commands.AddCommand.<GetPackageByInteractiveFlow>d__15.MoveNext() + 0x93b
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x72
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x93
   at Aspire.Cli.Commands.AddCommandPrompter.<PromptForIntegrationAsync>d__3.MoveNext() + 0x27f
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x72
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x93
   at Aspire.Cli.Interaction.ConsoleInteractionService.<PromptForSelectionAsync>d__27`1.MoveNext() + 0x4ef
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x99
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x93
   at Spectre.Console.SelectionPrompt`1.<ShowAsync>d__56.MoveNext() + 0x257
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x99
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x8b
   at Spectre.Console.ListPrompt`1.<Show>d__3.MoveNext() + 0x5b7
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x99
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task`1.TrySetResult(TResult) + 0x86
   at Spectre.Console.DefaultInput.<ReadKeyAsync>d__4.MoveNext() + 0x1af
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext, ContextCallback, Object) + 0xad
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1.AsyncStateMachineBox`1.MoveNext(Thread) + 0x5f
   at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(IAsyncStateMachineBox, Boolean) + 0x89
   at System.Threading.Tasks.Task.RunContinuations(Object) + 0x68
   at System.Threading.Tasks.Task.TrySetResult() + 0x74
   at System.Threading.Tasks.Task.DelayPromise.CompleteTimedOut() + 0x10
   at System.Threading.TimerQueueTimer.Fire(Boolean) + 0x4f
   at System.Threading.TimerQueue.TimerCallbackWindowsThreadPool(Void*, Void*, Void*) + 0x8e
--- End of stack trace from previous location ---
   at Aspire.Cli.Backchannel.AppHostAuxiliaryBackchannel.<CreateFromSocketAsync>d__30.MoveNext() + 0x1d7
--- End of stack trace from previous location ---
   at Aspire.Cli.Projects.RunningInstanceManager.<StopRunningInstanceAsync>d__6.MoveNext() + 0xb1
[09:40:38] [info] Stdout: ❌ Unable to stop one or more running Aspire AppHost instances. Please stop the application and try again.
❌ Unable to stop one or more running Aspire AppHost instances. Please stop the application and try again.
[09:40:38] [dbug] CliUpdateNotifier: Current version: 13.3.5
Newest stable version: 13.3.5
Newest prerelease version: (null)
[09:40:38] [dbug] CliUpdateNotifier: No newer version for the current version 13.3.5.
[09:40:38] [info] Program: Exit code: 5

Exceptions (if any)

No response

Aspire doctor output

SocketException (10061): No connection could be made because the target machine actively refused it.

Anything else?

No response

[joperezr]

🤖 Aspire triage pass — 2026-05-24 06:14 UTC

Area: area-cli
Kind: bug
Repro: yes-minimal — steps in issue body describe a clean repro from a fresh terminal session (no running AppHost), with full stack trace captured
Affected version(s): 13.3.5 (latest stable: 13.3.5)
Severity: S2 — core CLI scenario (aspire add) is fully blocked when no AppHost is running; RunningInstanceManager.StopRunningInstanceAsync attempts to connect to the auxiliary backchannel socket, gets SocketException 10061 (connection refused), and surfaces it as "Unable to stop one or more running Aspire AppHost instances" instead of treating "no instance running" as the expected state. Exit code 5.

Urgency: 🟡 vNext — recommend milestone 13.4
Reason: S2 in shipping bits with no workaround, clean repro in area-cli, but regression baseline vs. 13.2/earlier 13.3.x is unconfirmed by the reporter. Servicing (13.3.x) may be warranted if humans can confirm prior versions worked — flagged for human review.

Suggested owner(s): @JamesNK
Evidence:

• @JamesNK merged 40+ area-cli PRs in the last 90d, including direct touches to the backchannel / RunningInstanceManager / cancellation code path implicated by the stack trace: Handle canceled backchannel streams #17114 ("Handle canceled backchannel streams"), Fix CLI cancellation disposal race on shutdown #17179 ("Fix CLI cancellation disposal race on shutdown"), Move error handling from Program.cs to BaseCommand SetAction delegate #17310 ("Move error handling from Program.cs to BaseCommand SetAction delegate"), Refactor CLI commands to return CommandResult and centralize cancellation handling #17005 ("Refactor CLI commands to return CommandResult and centralize cancellation handling").
• No CODEOWNERS entry matched the cited Aspire.Cli.Backchannel / Aspire.Cli.Projects paths.

Confidence: medium
Needs human?: yes — servicing-vs-vNext decision needs confirmation of regression baseline (did aspire add work in 13.3.4 / 13.2?)

Dry-run mode — no labels or milestone applied. Reply /triage apply to promote, or edit and reapply.