Share via

Skype For Business / Lync Troubleshooting: online client can't connect

  • Article

Sometimes you will go through this type of error in your professional career where at client side you will experience a error like this that you added the proper Lync or Skype for business entries into their public DNS but after entries the correct entry you will still experience this type of error where you will not be able to connect the Lync or Skype for business. I got error when i tried to connect from the domain joined computer or network but when i tried to open from home or my computer rather than domain joined everything got fine and working like charm.

Actually, I had the same issue last week. i done everything i know but the error was there and i was't able to connect the Lync online. Actually my client had a Microsoft Threat Management Gateway known as TMG in their environment and had hybrid environment where maximum of their users were at Office 365 and some users were on-premises.

I just thought that may be i need to make a rule on **TMG **where i have to open the ports of Lync server i.e 5061 and i did it I allowed the 5061 port from the **TMG **Server but the error still existed. After a lot of struggling i just went to the Internet Explorer and made a changes which i have mentioned below and everything got fine.

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.