You’re repeatedly prompted for Exchange credentials after you sign in to Lync

Issue

After you successfully sign in to Skype for Business Online (formerly Lync Online) by using Lync 2010 or Lync 2013, you may experience the following issues:

You receive a message in Lync that says it cannot connect to Exchange.

You're repeatedly prompted to provide a user name and a password to connect to Exchange. You may also receive the following message: 

Credentials are required

 

Note The message that you receive may vary, depending on which service Lync is trying to connect to. You may be prompted for credentials when Lync tries to connect to any of the following services:

Calendar and Free/Busy information from Outlook

Exchange Web Services (EWS)

Response Group Service

Address Book Service

Solution

How to collect log files from Office Communicator, Lync, and Skype for Business Client

To create and collect log files from Office Communicator, Lync, or Skype for Business Client, follow these steps:

1.    Make sure that logging is enabled. To do this, use one of the following methods, as appropriate for your situation:

Skype for Business : Video Interop Server (VIS)

Video Interop Server (VIS)

VIS is a standalone server role implemented in on-premises deployment and provides interoperability with Cisco/Tandberg Video TeleConferencing endpoints (VTC) in this release. (Potentially, other systems will be included in future releases). VIS acts as B2BUA between SfB deployment and Video Gateway (CUCM).                                                                                                                              

Skype For Business : What is New

Microsoft has re-branded Lync 2013 Client as Skype for Business (SfB) Client and released that update on 14 April 2015. It will rebrand next version of Lync server as Skype for business (SfB) server 2015 and will release officially it on 1 May 2015. This article’s objective is to explain what new features it brings along.

Skype for Business: What’s New