The connection to the server is lost. The page will be refreshed to establish connection.


We have cnMaestro on premise, and ofter I get in my firefox this alert:

The connection to the server is lost. The page will be refreshed to establish connection.Schermata del 2018-07-30 16-42-20.png

I click OK, and the interface is refreshed, bringing me back to the start... so I have again to select sub folder ecc

There is something I can do to prevent it?

Thank you

cnMaestro UI uses web socket to communicate with server.

If the browser web socket disconnect quite often with cnMaestro server, the popup will come so that the new session is re-established.

Ideally this doesnt happen very frequently as long as the both the end is able to ping each other.


Hi Rupam,

thank you for your reply. My PC and our cnMaestro are in the same office on a Gigabit LAN. I don't think i lose packets but i'm investiganting (for now I using a ping - mtr to the cnMaestro VM).

Anyway, I noticed that "the connection to the server is lost..." happens more often if I switch tab in Firefox and the tab of cnMaestro stands in "background" for a while. Maybe firefox or my system put to sleep the websocket when not on the focused tab?


Yes if the system goes in sleep mode, socket will get disconnected.

If the tab is kept open and system is up, ideally it shouldnt disconnect.

This is an issue for us  as well.  Everyone in the office experiences this every 5 minutes (almost when the polling takes place) and the system has plenty enough resources.  I use firefox but others use chrome and experience the same thing.  I keep a ping open to the system and none drop.  Its a session thing. 

I'd like to never have to refresh except maybe every 60 minutes.   This is an ON PREM virtual machine.