title: Shared Web Credential failed to approve on iOS 10 real devices
body: <p>recently a problem appeared in my iOS application. I'm using Shared Web Credential to get associated user credentials:</p>
  
  <pre><code>SecRequestSharedWebCredential(0, 0, ^(CFArrayRef lpCredential, CFErrorRef lpError) {
      // stuff
  });
  </code></pre>
  
  <p>It was working fine until recently, when I discovered it stopped working on iOS 10 devices (possibly only 10.2 devices but I don't have older versions to check). Everything should be in order (entitlements, signed apple-app-site-association file on the server) as it works on iOS 9 and 8. Also it works on every version in simulator (even 10.2).</p>
  
  <p>But on real devices iOS 10 it doesn't work. Completion block is called with error code </p>
  
  <p><code>-25293 (Authorization/Authentication failed.)</code></p>
  
  <p><code>"www.webcredentialsurl.com" failed to approve "AppPrefix.AppID"</code></p>
  
  <p>Does anybody have any idea what might be causing this? Did Apple change something recently? I'm using Xcode 8.2.</p>