“A specified communication resources(port) is already in use” when attaching the debugger

Question

I have just upgrade my windows phone 8 to windows phone 8.1. When I connect my phone to pc and run my project it gives me

Answer 1

I had exactly the same problem. In my case installing Update 4 RTM for VS 2012 helped and I could once again debug my apps (previously, I had Update 4 RC installed). However, the error still appears if I open VS 2012 and VS 2013 side by side - if only one of them is open at the time then the error won't pop up.

Updating to Vs2012 Update 4 RTM, then we can debug on Phone

Answer 2

We need to update visual studio 2012

Go to Tools->Extensions and update->updates and update the visual studio update 4

Answer 3

Project GUID conflict

Yet another possible reason for this error is the Project GUID conflict. If the project / app GUID of the application you are trying to debug is the same as the GUID of another application installed from the store (can be the same application, and doesn't matter if you already uninstalled it), this error may occur.

I was testing in-app purchases for my app for which purpose I had to change the app GUID in WMAppManifest.xml and AssemblyInfo.cs to the GUID from the Windows Phone Store. Having the app installed from the store itself (for testing purposes) previously, I uninstalled it for the purpose of debugging. Yet that didn't help and anytime I changed my app GUID to match Windows Store App Guid I got this error. Changing the GUID back to the original project's GUID caused the error to go away and debugging was working well again.

VS2013 Ultimate Update 2, testing with 8.1 Device.

Answer 4

You may need to deploy the app on the phone before debug mode can be ran. Right click the project and select Deploy. Use this link to see more detailed information.

Answer 5

If you're getting this error when trying to debug a Xamarin App targeting a Windows Phone emulator, make sure you have Deploy ticked for the WinPhone project:

Solution > Properties > Configuration Properties > Configuration

Answer 6

1. Close VS
2. Delete the files from C:\Users\Luke\AppData\Local\Microsoft\Phone Tools\CoreCon
3. Open VS and hopefully you can deploy

Source: @Stadler (https://connect.microsoft.com/VisualStudio/feedback/details/772570/wp8-emulator-a-specified-communication-resource-port-is-already-in-use-by-another-application)