Troubleshooting EWS issues in LYNC 2013

First of it is important to understand how the EWS integration works in LYNC.
Lync uses the following DNS-based discovery method
http://<smtpdomain>/autodiscover/autodiscover.xml https://<smtpdomain>/autodiscover/autodiscover.xml
http://autodiscover.<smtpdomain>/autodiscover/autodiscover.xml
https://autodiscover.<smtpdomain>/autodiscover/autodiscover.xml
SRV: _autodiscover._tcp.<smtpdomain>

So wery often I see customers having a perfectly good working autodiscover setup, seen from Outlook because it utilizes SCP in AD – and when LYNC is deployed integration fails.

So which features are serviced by EWS:
Conversation History
Missed Conversations
Missed Calls
Voice Mail Playback
High-Resolution Photos on contacts
Meeting tab – with meetings from calendar
Contact Information Presence based on Calendar Information
And Unified Contact Store

So EWS is extremely important for LYNC to work correctly
And therefor DNS based autodiscover needs to be setup corrently.
Please note that if EWS fails LYNC will failback to MAPI for some features

Also internal URL for EWS needs to be configured on Exchange – more info: http://technet.microsoft.com/en-us/library/aa997233(v=exchg.150).aspx

When all the above is set correct , and EWS integration still fails – well.. start diggin 🙂

First off, lets get an idea of what LYNC actually tries to do.

Sign in to local pc as the failing user, and with LYNC client running, find the LYNC icon in systray – press CTRL and rightclick icon and select “configuration information”

Check to EWS URL lines, and EWS status.

IF EWS not deployed shows up then first thing to check is this reg key:

Start regedit.exe
Go to HKLMsoftwareMicrosoftofficeoutlookaddinsUCAddin.LyncAddin.1
Make sure that value of “LoadBehavior” is = 3, if not then change it to 3

Note: It might be under HKLMsoftwareWow6432NodeMicrosoftofficeoutlookaddinsUCAddin.LyncAddin.1