Consider the following scenario:
Microsoft Lync Room System's mailbox account is on Microsoft Office 365.
When Lync Room System starts, the Front Room Display and the Console Display show the room's calendar information.
You schedule a new meeting with the room.
In this scenario, the new meeting does not show up on the Front Room Display and Console Display.
When you start Lync Room System, it makes streaming connections to Office 365 mailbox by using Exchange Web service (EWS), which reaches the maximumnumber of concurrent subscriptions of Office 365 mailbox. Once the maximumnumber of concurrent subscriptions is reached, the Calendar in Lync room system cannot be updated.
To resolve this issue, install the following cumulative update:
2929207 Update for Lync Room System: April 2014