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:

Enable IM Mute

Turn off IM in a Lync Meeting (Enable IM Mute)

Turning off instant messaging (IM) in a Lync Meeting allows you to help participants stay focused on the meeting content. You can disable IM when scheduling the meeting or during it.

Keep in mind that when you disable IM at the time of scheduling, you can’t turn it back on during the meeting. But if you turn off IM during a meeting, you can turn it back on at any time, to allow shared conversation.
To disable IM when scheduling, you must have Outlook.

Disabling IM when scheduling a Lync Meeting

1. On your Outlook ribbon, click New Lync Meeting.
2. Click Meeting Options on the ribbon.
3. Under Do you want to limit participation?, click Disable IM.
4. Click OK and set up the rest of your meeting as you normally would.

Disabling IM during a Lync Meeting

Any of the presenters can turn IM off or on during the meeting, if it hasn’t been disabled at the time of scheduling.

1. In the meeting window, point to the people icon.
2. Click the ACTIONS tab
3. Click No Meeting IM.

Lync notifies the meeting participants that the IM has been turned off.

To turn IM back on, go back to the ACTIONS tab, and click Allow Meeting IM.

Upgrading Polycom CX series phones for Lync Server

Step 1: Obtain the latest updates from Microsoft website, Store the .cab file in C:\Polycom
Step 2: Find the web server identity in pool

• Get-CsService

Step 3: Construct the command in notepad

Import-CsDeviceUpdate -Identity "service:xxxxxxxx" -FileName C:\Polycom\UCUpdates.cab

Step 4: Run it in Lync Server Management Shell

Step 5: Verify import in Lync control panel

Step 6: Approve it after hours.

The Device Update Process

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The device update process begins with you downloading an update from the Microsoft website, and then using the Lync Server 2010 Control Panel to test, approve, or reject the update. Approved updates become pending updates that devices retrieve by using the following process.
The first time a user starts an IP phone and signs in, the device gets information by using in-band provisioning from the server. The information contains the internal URL of the server running the Device Update Web service.
If the device is turned on, but no user signs in, and no user has ever signed in on the device, then the device sends a DNS lookup request to ucupdates-r2.<DNSDomainNameProvidedByDHCP>, and obtains the internal URL of the server running the Device Update Web service.
The device checks for updates every time it is turned on, every time the user signs in, and every 24 hours, by default. It checks by sending an HTTP request over port 443 to the Front End Server that hosts the Device Update Web service. The request includes the current version of software that the phone is running, and the response is determined by the device and whether there is a new update on the server to download.

Lync 2010 Client Version Lists

For quick reference, the following table lists the versions, release month, year, and a link to the KB article for all Lync 2010 updates released through March 2013.

Force Lync2010 Client to update Address book

Step 1 : Update Servers

Run following command from Lync Server Management Shell

Update-CsAddressBook –Verbose

Step 2: Update Clients

Run following command from cmd ( run as an Administrator )

reg add HKLM\Software\Policies\Microsoft\Communicator /v GalDownloadInitialDelay /t REG_DWORD /d 0 /f

Exit the Lync client and delete the GalContacts.dband GalContacts.db.idxfiles from the user’s profile directory ( following location )

%userprofile%\AppData\Local\Microsoft\Communicator\sip_<username@domain>\

Log back in and Lync client will now update the address book.