Lync 2013 or Lync 2010 can't connect to the Skype for Business Online service because a proxy is blocking connections from MSOIDSVC.exe

Applies to: Skype for Business OnlineMicrosoft Lync 2013Lync 2010

PROBLEM


You may experience the following issues in Lync: 
  • Lync 2013 or Lync 2010 can't connect to the Skype for Business Online (formerly Lync Online) service through a proxy that is configured by using a file://-based Proxy Auto-Configuration (PAC) file.
  • You can't connect to the Skype for Business Online service when you're using Lync 2013 or Lync 2010. When you view Network Monitor, traces show multiple TCP SYNC requests for login.microsoftonline.com.

    Screen shot of network monitor, showing multiple TCP sync request for login.microsoft.com

SOLUTION


To resolve this issue, use one of the following methods, as appropriate for your situation.

MORE INFORMATION


This issue occurs when the Microsoft Online Services Sign In Assistant traffic doesn't go through the TMG firewall client, and a direct connection is attempted.

For example, this issue may occur in a scenario where all the following conditions are true:
  • Proxy Server Automatic Discovery isn't enabled.
  • A proxy server isn't configured in Internet Explorer.
  • The Automatically detect settings option isn't enabled in Internet Explorer.

    Note The only location that the Lync and Skype for Business clients use to detect network proxy configuration information is in the LAN settings option on the Connections tab in Internet options.
For more information about the WinHTTP limitations of supporting a file-based proxy, go to the following Microsoft website:

Still need help? Go to Microsoft Community.