Consider the following scenario:
The administrator sets the Participation policy to Formal in Microsoft Lync Server 2013 Control Panel.
You are a formal agent of multiple response groups in difference front-end pools in the Lync Server 2013 environment.
You open the agent sign-in page by clicking Response Group Settings on the Tools menu in a Lync client.
In this scenario, you may receive one of the following messages intermittently:
You were removed as an agent
You were added as an agent
Additionally, it may take a long time to load the agent sign-in page. Occasionally, the page loading times out. When this issue occurs, you cannot sign in to the response groups that are not displayed on the page.
This issue occurs because the front-end pools list that the Response Group service creates is incomplete. Therefore, the Response Group service does not query the pools that are not in the list.
To resolve this issue, install the May 2015 cumulative update for the Lync Server 2013 Response Group service.
Note After you apply this update, the administrator may have to increase the time-out value of the server that is running IIS in an environment that has many response groups deployed. Otherwise, the agent sign-in page may time out in one minute (the default time-out value) when it waits for the complete response group list to be constructed.