For security purposes, a Horizon administrator can set timeouts that log you off of a server after a certain number of hours and that lock a remote application after a certain number of minutes of inactivity.
If you have not used a remote application for a certain amount of time, you receive a warning prompt 30 seconds before the application is automatically locked. If you do not respond, the application is locked. By default, the timeout occurs after 15 minutes of inactivity, but your Horizon administrator can change the time period.
For example, if you have one or more applications open and you walk away from your computer, the 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 application windows appear again.
The server timeout period is typically set for a certain number of hours of inactivity. By default, you are required to log in again if you have Horizon Client open and connected to a particular server for more than 10 hours. This timeout applies to both remote application and remote desktop connections.