The document timeout on a server is set to 480 min. The "Maximum Inactive Session Time" is set to 30 min. It is the case generally set up for the whole QlikView server (Server -> Performance), and for IIS.
Idle timeout is not specifically defined inside the application. When the end users log on QlikView and access this particular application, everything work fine, but when the end users log on the system via VPN, the session for this application time outs after 5-10 minutes!
When looking into the session.log file I always find the following for this application "Socket closed by client..." as "Exit Reason"!
This only occurs for this particular application and not other applications on this server.