Lync Control Panel is not opening HTTP Error 401.1 – Unauthorized

Hi Readers, Just sharing a situation where after migration of Lync servers to New datacenter We started getting intermittent errors in Lync Control panel. The only change was server ip addreses. Below is the resolution that we had done: Edited the below key under: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0 BackConnectionHostNames (Multi-String) If it doesn’t exist in your environment just create…

Communicator/Lync Presence in outlook stopped working

Hi Readers, Some of the users reported that their Communicator/Lync  Presence in outlook stopped working. On further analysis  it is found that users have installed another IM client (Cisco Jabber) for testing purposes. There is a registry key that gets set when another IM client is installed. HKEY_CURRENT_USER\Software\IM Providers DefaultIMApp:  We have uninstalled the Jabber client &…