For security purposes, a Horizon administrator can set timeouts that log you off a server and lock a published application after some period of inactivity.
By default, you must log in again if you have Horizon Client open and are connected to a particular server for more than 10 hours. This timeout applies to both remote desktop and published application connections.
You receive a warning prompt 30 seconds before a published application is locked automatically. If you do not respond, the published application is locked. By default, the timeout occurs after 15 minutes of inactivity, but a Horizon administrator can change the timeout period.
For example, if you have one or more published applications open and you walk away from your computer, the published application windows might no longer be open when you return an hour later. Instead, you might see a dialog box that prompts you to click OK so that the published application windows appear again.