title: Production app: Invalid or unknown client (ID copied from credentials page)
body: <p>I went through the sandbox testing and graduation procedure. My application got approved (for internal use), but I've been unable to use the new client ID.</p>
  
  <p>The OAuth callback URL contains the error message:</p>
  
  <pre><code>GET /oauth2callback?error=invalid_request&amp;error_description=OAU-230%3AInvalid%20or%20unknown%20client%3A%20xxxxxxxclientIdxxxxx
  </code></pre>
  
  <p>I copied my client ID several times from the application credentials page, it is correct and complete. The ID is repeated correctly inside the error message as well, so I know it's received on the production server. The production server URL is correct too.</p>
  
  <p>What's going on here?</p>