Network Programming in .NET

If you have an app on VSTS, which suddenly started returning the error
{“Error”:”unauthorized_client”,”ErrorDescription”:null} and InvalidScope in the query string, then it appears that the culprit is vso.codesearch, which needs to be removed from the scope.

Unfortunately, if you already have created an app with this in it’s scope, then a bug in VSTS prevents you from saving it again – so you may need to create a duplicate of the app.