UWP Enable local network loopback

M4s0n picture M4s0n · Oct 21, 2015 · Viewed 22.9k times · Source

I wrote a UWP-App and after generating and installing the .appxbundle, every time I start the App I get a net_http_client_execution_error. The App is starting and running fine, when started in Visual Studio 2015. So there is no chance for me to get the problem, if I debug the app.

Update:
By default Windows restricts apps to reach the localhost (127.0.0.1). I have running a couch database there. This couch database should run there for our costumers as well. Is it possible to allow a App to reach the localhost (enable local network loopback)?

Answer

Rob Caplan - MSFT picture Rob Caplan - MSFT · Oct 21, 2015

For a line of business app use the checknetisolation.exe tool to grant the app a loopback exception.

To enable loopback use this command:

c:\>checknetisolation loopbackexempt -a -n=<package family name>

To disable loopback use this command:

c:\>checknetisolation loopbackexempt -d -n=<package family name>

The package family name for a UWP app can be found in several places: Visual Studio shows it in Package.appxmanifest editor on the packaging tab, PowerShell's get-appxpackage cmdlet displays it, etc. It will look something like "MyPackage_edj12ye0wwgwa"

In some cases loopback exemption will work for some time and then stop working. In this case you might need to run the following command to clean/remove all exemptions and then add them back one by one to get back in a good state. (from Pawel Sledzikowski's comment)

c:\>checknetisolation loopbackexempt -c

There is a whitepaper with more details at https://msdn.microsoft.com/en-us/library/windows/apps/dn640582.aspx