Enter the sign-in address that you're using when you to try to sign in to Skype for Business Online (for example, and start the test. To verify that the Lyncdiscover CNAME record is present in the Domain Name System (DNS) records, go to the Lync Connectivity Analyzer, and select Office 365 Custom/Vanity Domain Name Settings Test for Lync. Step 1: Verify the Lyncdiscover CNAME record To troubleshoot this issue, follow these steps. Also please check the network connection, sign-in address and server addresses. However, the user receives the following error message: Cannot connect to the server.

'Cannot connect to the server' error message when Skype for Business Online users try to sign in to the Lync 2010 mobile client on a mobile deviceĪ Skype for Business Online (formerly Lync Online) user tries to sign in to the Lync 2010 mobile client from a Windows Phone, Apple iPhone or iPad, Google Android, or Nokia Symbian device by using the Auto-Detect Serveroption to determine the Skype for Business Online server.