How to Debug Remote MAUI App Launch

Question

How to Debug Remote MAUI App Launch

Marc George 191

I have a .NET 9 MAUI app being deployed to a remote Xcode iOS iPhone 16 Plus. All components have the latest release software. The deployment is successful, and the application is launched and the splash screen displayed on the phone. However, the first line of code, "InitializeComponent()" with a breakpoint applied is never reached. The app is terminated and the following debug output is generated.

INFO: Closing debug connection from device (USB) INFO: Disposing input and output streams... ERROR: An error occurred when writing to the output stream. Details: net_io_readfailure, Operation canceled INFO: Disposing input and output streams... INFO: Closing debug connection from remote debugger (TCP) ERROR: An error occurred while writing to the debug stream. Details: ObjectDisposed_Generic ObjectDisposed_ObjectName_Name, UsbStream INFO: Disposing console and debugger streams... INFO: An error occurred while forwarding HotReload local tunnel: System.IO.IOException: USB connect timeout (ENODATA), likely because the app failed to launch. Please review device logs and/or crash reports for more information. at Xamarin.MacDev.AggregateAsyncResult.CheckError(Boolean cancelled) at Xamarin.MacDev.IPhoneDevice.EndConnectStream(IAsyncResult result) at System.Threading.Tasks.TaskFactory1.FromAsyncCoreLogic(IAsyncResult iar, Func2 endFunction, Action1 endAction, Task1 promise, Boolean requiresSynchronization) --- End of stack trace from previous location --- at Xamarin.Messaging.IDB.IPhoneUsbLocalTunnelConnection.StartLocalTunnelAsync() at Xamarin.Messaging.IDB.LaunchAppMessageHandler.ForwardLocalTunnelsAsync(LaunchAppMessage, IPhoneDevice) ERROR: [iOS HotReload] Failed to connect to "iRogue" over USB on port 11000.

What is necessary to debug/fix the problem?

10 answers

Your answer

Answer 1

Gade Harika (INFOSYS LIMITED) 330 Microsoft External Staff

Thank you for sharing the details

If you're still seeing debugger tunnel failures on port 11000 or wondering whether it’s actually open, the key thing to remember is that Visual Studio uses that port as a local bridge for USB communication—it’s not an internet-facing port that needs traditional firewall “open” rules. It just needs to be free, accessible, and unblocked locally on your development machine or Mac build host.

If you're dealing with debugging issues, especially MAUI app crashes before InitializeComponent() runs, you can isolate root causes by:

Disabling Hot Reload (it often destabilizes the tunnel)

Checking whether another app is occupying port 11000 (netstat -ano)

Inspecting crash logs in Xcode’s Devices window

Testing the app over Wi-Fi instead of USB

Deploying a minimal MAUI app to check baseline behavior

And if you're planning to try Android next week, you’ll likely have smoother results—Android debugging uses ADB rather than WebSocket tunnels, and is usually less sensitive to port issues.

Let me know if the issue persists after following these steps. I’ll be happy to assist further if needed.

Marc George 191 Reputation points

2025-07-09T17:21:52.53+00:00

It appears that VS might be using UDP, not TCP:

PS C:\Users\Alaskan> portqry -n 192.168.1.36 -e 11000 -p both Querying target system called: 192.168.1.36 Attempting to resolve IP address to a name... Failed to resolve IP address to name querying... TCP port 11000 (unknown service): NOT LISTENING UDP port 11000 (unknown service): LISTENING or FILTERED

This however this doesn't change the presence of the original problem. This issue has been reported to the VS team.
Gade Harika (INFOSYS LIMITED) 330 Reputation points Microsoft External Staff

2025-07-10T06:37:26.02+00:00
Thank you for sharing the details and debug output.

It appears that Visual Studio is using UDP on port 11000, which may be filtered or not listening on the target machine. To resolve this, please:

Ensure UDP port 11000 is allowed in the firewall on the target machine.

Verify that both machines are on the same network, and there's no VPN or proxy interfering.

Consider using an Android device with ADB for debugging — it's more stable and avoids WebSocket or port-based issues.

Let us know if the issue persists after these steps — we’ll be happy to help further!

Answer 2

Thank you for sharing the details and debug output.

Here are a few steps you can try to resolve this:

Recommended Troubleshooting Steps:

Ensure Unpacked Deployment: Since remote debugging requires deploying an unpackaged version of your app, make sure you are following the steps outlined for publishing your app using the CLI or by modifying your launch settings. You can check the process in the "Remote Debugging a .NET MAUI app" documentation to ensure that the deployment is correct.

Update All Software: Ensure that Xcode, iOS on your iPhone, Visual Studio, and .NET MAUI workloads are all up to date.
Trust the Computer on iPhone: Reconnect your iPhone via USB. Make sure the device trusts the Mac/PC, and check for the "Trust This Computer" popup on the phone.
Reset USB Connection: Disconnect and reconnect the iPhone. Use a different USB cable and USB port. Restart both your development machine and the iPhone.
Check Device Logs and Crash Reports: Open Xcode > Devices and Simulators, select your device, and review the device logs for app crash or launch issues.
Kill rogue mtouch processes (Mac only): Sometimes background processes like mtouch or launchd interfere. Restarting the machine or manually killing such processes via Terminal might help.
Disable Hot Reload Temporarily: In Visual Studio, disable Hot Reload for MAUI and try deploying again to isolate the issue.
Manual Provisioning Profile Check: Ensure correct provisioning profiles and code signing are set for the app in Visual Studio > iOS Bundle Signing.

If the issue persists after following the above steps, please let us know the following for deeper investigation:

Visual Studio version

.NET MAUI version

Xcode and iOS versions

Whether the same issue occurs on a simulator

We’ll be glad to help further based on the additional details.

Marc George 191 Reputation points

2025-07-03T23:36:18.02+00:00

Attached are the details of the VS environment installed. Also below are two screen shots of the ending results of both the Xcode and simulator builds. The Xcode build displays the splash screen before terminating. The simulator build does not display itself.

Microsoft Visual Studio Enterprise.txt

Answer 3

Thank you for sharing the details and debug output.

Here are a few steps you can try to resolve this:

This indicates Hot Reload or remote debugging transport is being blocked or unstable, usually because of:

Improper provisioning/profile signing
Background USB/mTouch or usbmuxd process conflicts
Tunnel or port (11000) being blocked or timed out
Hot Reload instability or incompatible versions
Device trust/certificate or app sandboxing crash

Steps to Fix It

Fully Disable Hot Reload and Fast Deployment

Hot Reload is known to cause debug tunnel failures on real devices.

Go to Tools > Options > Debugging > .NET MAUI Hot Reload

Disable both Hot Reload and XAML Hot Reload

Rebuild and deploy again.

2. Manually Kill Background USB Debug Processes

On your Mac machine (remote builder), run:

sudo killall -9 usbmuxd

sudo killall -9 mtouch

Then reboot the Mac, reconnect the iPhone, and trust the computer again. This clears stale port bindings.

3. Use Wi-Fi Deployment Instead of USB

If USB is flaky:

Connect both iPhone and Mac to same Wi-Fi.

In Visual Studio:

Go to iOS project > Properties > iOS Debugging

Enable wireless debugging

Then re-pair the iPhone and try again.

4.Clean Build Artifacts

Manually delete bin and obj folders

Then run:

Check Code Signing & Certificates

Your screenshot shows manual provisioning. Ensure:

Apple Dev Certificate is not expired

Provisioning profile matches app ID and bundle

In Visual Studio: Tools > Options > Xamarin > Apple Accounts — re-sync all identities

You can also revoke and recreate the provisioning profile.

Update Everything

Visual Studio 2022 (latest)

Xcode 16.4+ with latest command line tools

.NET MAUI SDK (dotnet --list-sdks) – ensure latest

iPhone iOS version must be compatible with Xcode

Use:

dotnet workload update

Check Mac Logs

On the remote Mac, check this log:

~/Library/Logs/Xamarin/mtouch.log

Look for provisioning, signing, or tunneling errors.

8. Test with a Simulator

Try running the same MAUI app on an iOS Simulator instead of a real device. If the simulator works, issue is with:

USB transport

Code signing

Device provisioning

Temporary Workaround

Until remote debug is resolved:

Use Release build with manual logging (e.g., System.Diagnostics.Debug.WriteLine) to file, then inspect via Console.app or Device Logs.

Or, run on iOS Simulator until deployment works.

Let us know if the issue persists after following these steps. We’ll be happy to assist further if needed.

Marc George 191 Reputation points

2025-07-04T20:48:37.1966667+00:00

All three VS Hot Reloads were already off.

No process were running to kill on the Mac.

Rebooted and reattached phone. No Trust prompt.

Can't find "Properties > iOS Debugging" to enable wireless debugging in VS

Rebuilt receiving the attached error output. Interesting that HotReload used and reported as an error is present as it was in the previous output.

App Termination.txt

Both devices placed on the same Wi-Fi network. iPhone seen by Mac but as a Personal HotSpot. iPhone is wirelessly pair to Xcode. iPhone port 11000 is not listening. Port 62078 is listening.

Profiles and certificates new and valid.

The SDK's are

9.0.200-preview.0.24575.35 [C:\Program Files\dotnet\sdk] 9.0.300 [C:\Program Files\dotnet\sdk] 9.0.301 [C:\Program Files\dotnet\sdk]

iOS 18.5

Using the simulator, the app is deployed and is launched loading a large number of assemblies but terminating after the display of a blank phone with the results of

INFO: Closing debug session after launching on simulator... The app has been terminated. The app has been terminated.

I am still attempting to finalize the setup of wireless. The device is shown as wirelessly paired with Xcode, but the device is not present in the VS remote targets list. Note that on the Mac, the device is not present in the Finders locations list.

What seems important is the port issue of 11000 vs 62078 which is the documentation stated port.
Marc George 191 Reputation points

2025-07-04T20:52:53.89+00:00

I am planning on changing the iPhone to be used for testing purposes.

Answer 4

Thank you for your detailed update and for trying the earlier steps. Based on your latest findings, it looks like we're getting closer to isolating the issue. Please follow the updated steps below to resolve the remaining blockers.

Reset Trust on iPhone

On your iPhone, go to:

Settings > General > Transfer or Reset iPhone > Reset > Reset Location & Privacy

Reconnect your iPhone to the Mac via USB and ensure you see and accept the "Trust This Computer?" prompt.

Disable Personal Hotspot

Please turn off Personal Hotspot on the iPhone:

Settings > Personal Hotspot > Allow Others to Join → Turn OFF

Ensure both your Mac and iPhone are connected to the same regular Wi-Fi network (not via hotspot).

Port Forwarding (If Needed)

Visual Studio expects port 11000, but your device is only exposing 62078.

You can forward the port using iproxy:

brew install usbmuxd

iproxy 11000 62078

This maps port 62078 to 11000 for proper communication.

Enable Wireless Debugging

Open Xcode > Window > Devices and Simulators

Select your iPhone and ensure “Connect via network” is checked.

Check iPhone in Visual Studio

Restart both Mac and Visual Studio.

Navigate to Debug > iOS Remote Devices and confirm the iPhone now appears in the remote targets list.

Additional Notes:

Since you mentioned planning to switch devices, testing on a different iPhone may help rule out hardware-specific issues.

If the problem persists, please share updated logs (especially after trust and port configuration) so we can dig further.

Marc George 191 Reputation points

2025-07-08T10:45:31.85+00:00

Trust has always been presented when connecting and Hot Spot not enabled. There has always been only one network, and every device is connected to it.

Xcode is paired with the phone.

Neither brew or iproxy is available on the phone or in the stores. I see is available on the Mac but not iproxy. It appears to require an external server by a provider.

The iPhone has reappeared in the targets list; the reason for the previous test results.

After consideration of the testing procedures and results to date, I decided to test the iPhone's ports themselves again not using the Mac but wirelessly with the Windows IDE. These are the results:

Given the results, forwarding 62078 to 11000 doesn't make sense. It appears that the current VS debugging extension is targeting the wrong port and needs to be fixed. The only other possibility is adding an interface to iOS that opens 11000 which doesn't make sense. 62078 was working just fine before. Note: I am now out of the office until next Monday,

Answer 5

Thank you for sharing the details and debug output.

Here are a few steps you can try to resolve this:

Based on the latest findings and recent discussions in the developer community, here's a clearer picture of what's likely happening with your remote debugging issue in .NET MAUI on iOS:

Root Cause Summary

The core issue appears to be Visual Studio's remote debugger expecting communication over port 11000, while modern iOS devices (especially with iOS 17/18) are only exposing port 62078, which is the standard port used by usbmuxd for device communication.

This mismatch leads to:

Debugger tunnel failures

Hot Reload connection errors

App termination before InitializeComponent() is reached

Why Port 11000?

Port 11000 is used by Visual Studio’s Hot Reload and debugger tunnel to communicate with the app on the device. However, if the app crashes or the port isn't opened by the app (due to provisioning, sandboxing, or iOS restrictions), the debugger cannot attach.

Why Forwarding 62078 to 11000 Doesn’t Work

Port 62078 is managed by usbmuxd and is used for general device communication, not app-specific debugging. Forwarding it to 11000 doesn't help because:

The app itself must open port 11000 for the debugger to connect.

iOS sandboxing may prevent this unless the app is properly signed and provisioned.

Recommended Workaround

Since all other steps have been exhausted, here’s a practical workaround:

1. Use Manual Logging Instead of Debugger

Temporarily replace breakpoints with logging:

System.Diagnostics.Debug.WriteLine("Reached InitializeComponent");

Then view logs via:

Xcode > Devices and Simulators > Device Logs

Or use Console.app on the Mac

2. Run in Release Mode with Logging

This avoids debugger attachment entirely and helps isolate whether the app is crashing due to debugger or runtime issues.

3. Use Simulator for Debugging Logic

Since the simulator works (even if it terminates), try:

Stripping down the app to a minimal version

Gradually reintroducing components to isolate the crash

References

Unable to debug iOS MAUI app · Issue #15065 · dotnet/maui - GitHub

Let us know if the issue persists after following these steps. We’ll be happy to assist further if needed.

Marc George 191 Reputation points

2025-07-08T14:10:47.8266667+00:00

if the app opened the 11000 port, what else needs to be done to enable the debugger to perform its activities?
Marc George 191 Reputation points

2025-07-25T10:14:51.77+00:00

I added a new comment to the VS team comment chain this morning because I found that after a USB debug failure and stopping the activity, VS continued to attempt activities involving the Mac all night.

Because of all the changes made to debug and fix the issue, I lost and have not been able to re-establish wireless connection to the iPhone. I have replaced the Xcode project and provisioning but that has not helped. Xcode does wirelessly connect to the iPhone.

I have updated VS, Xcode, OS's and libraries, but no change.
Gade Harika (INFOSYS LIMITED) 330 Reputation points Microsoft External Staff

2025-07-25T12:29:00.7033333+00:00

Thanks again for your detailed update.

Here are a few steps that have helped other users resolve similar issues:

Clear Visual Studio cache and re-pair with Mac

Delete these folders:

`C:\Users

[YourUser]\AppData\Local\Xamarin\MonoTouch-~/Library/Caches/Xamarin` on the Mac

Reboot both machines and re-initiate pairing from Visual Studio.

Re-enable wireless debugging

Connect iPhone via USB.

Open Xcode → *Devices and Simulators* → ensure **Connect via Network** is enabled. Disconnect USB and confirm the wireless icon is present. In Visual Studio, confirm “Debug over WiFi” is enabled in settings. **Check firewall settings and port usage** Make sure ports like 10000 (used by Xamarin) are open and not blocked by any firewall. **Try with a clean test project** Create a new minimal iOS project and test wireless debugging to rule out project-specific issues.

Gather logs for deeper insight

In Visual Studio, go to Help → Xamarin → Zip Logs and share them—this may reveal silent errors or clues.

Let us know if the issue persists after following these steps. We’ll be happy to assist further if needed. If the issue has been resolved, kindly mark the response as answered."

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How to Debug Remote MAUI App Launch

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