If you're experiencing sign-in issues using Microsoft Lync 2010 together with Microsoft Lync Online in a Microsoft Office 365 environment, see How to troubleshoot sign-in issues in Lync Online from Microsoft Support.

This article details how to troubleshoot sign-in issues and includes the following topics:

  • Scoping the sign-in problem
  • Lync Online sign-in error messages
  • Resolve Lync 2010 client-sides issues
  • Resolve Lync cached endpoints
  • Resolve certificate-related errors in Lync 2010
  • Resolve DNS and network-related sign-in problems
  • Bypass Lync 2010 Autodiscover and DNS resolution
  • Resolve user identity and Office 365 authentication system issues in Lync 2010
  • Next steps

Lync Server Resources

We Want to Hear from You