Technical Tip: How to fix CLI error message 'Connection lost. Press Enter to start a new connection' in the GUI

This article describes how to fix the CLI error message 'Connection lost. Press Enter to start a new connection in the GUI.

• Try with another browser.
• If it works with another browser, clear the cache and cookies of the browser where the error message appears.
• Use the incognito mode if using Google Chrome or private browsing if using Mozilla Firefox.

Some browsers allow users to refresh the cache for individual websites without affecting other cached content.

In Google Chrome, Microsoft Edge, or Brave: 'Right-click' any page element -> Inspect.


'Right-click' Reload button -> Empty Cache and Hard Reload.


Firefox and Safari do not support emptying the cache for an individual website.

If a browser issue persists after completely clearing the browser cache and trying different access methods, there may be a GUI issue on the FortiGate. If the device has a valid support contract and clearing the cache does not resolve, collect the initial diagnostic information listed in the article 'Collect GUI slowness and errors debugs' and reach out to FortiGate TAC.

Note :  Refer to Troubleshooting Tip: CLI Console frequent 'Connection Lost' after enabling web-svc-perf under log setting  for similar errors related to the 'Connection Lost' symptoms described above. It explains a situation where turning on web-svc-perf (available from FortiOS version 7.4.10, 7.6.5)  in the log settings unexpectedly restarts the Node.js process, which then causes the CLI console in the GUI to disconnect.

Related article:

Technical Tip: Fix CLI console from FortiGate GUI

Troubleshooting Tip: CLI Console frequent 'Connection Lost' after enabling web-svc-perf under log setting