The users are randomly disconnected from the XenDesktop sessions.
To resolve the issue, complete the following steps:
Click the Licensing tab in Citrix Desktop Studio.
Select the appropriate XenDesktop edition and XenDesktop licensing model from Edit product edition console.
Log on to the licensing server and ensure that the total number of users in use corresponds to the total number of licenses purchased.
XenDesktop is running out of licenses, new connection causes existing connection to get disconnected, and the following errors might be logged in the event viewer:
Event ID: 1154 This controller has entered the licensing grace period.
Event ID: 1163 No connection license available. To resolve, free licenses by closing sessions that are not needed, or add more licenses.
CTX128013 - FAQ: XenDesktop 5.x Licensing