Web Service and Server connection troubleshooting

Important

Visual Studio App Center is scheduled for retirement on March 31, 2025. While you can continue to use Visual Studio App Center until it is fully retired, there are several recommended alternatives that you may consider migrating to.

Learn more about support timelines and alternatives.

There are several common reasons why your app may have trouble communicating with a server or web service:

  • The endpoint the user is trying to connect to doesn't allow communication through the Test IP addresses. 
  • Geofencing is blocking communication with our servers in Denmark.
  • Additional time is needed for the communication to reliably complete.
  • If a secondary app is required, or the connection process requires taking your app being tested out of focus. App Center Test allows single app automation, not multiple apps, or system processes.

Allow List

If any of the following are blocked, you may need to explicitly allow them for your connection:

  • testcloud.xamarin.com (to allow incoming/outgoing traffic on ports 80 and 443)
  • These IP addresses:
    • 195.249.159.238
    • 195.249.159.239

See also

App Center Test Security - Personal Data in Tests