Troubleshooting Tip: FortiGate GUI freezes when editing IPSec VPN tunnel

To resolve this issue:

• Check if a known problem with characters in the VPN name causes the issue.
• Try changing the name of the VPN tunnel to remove any special characters, such as forward slashes. Prefer to use dash, hash tag, dots ( -,#, .) in VPN names. 

To change the name, use the following commands:

config vpn ipsec phase1-interface     rename <string> to <string> end

• Restarting the HTTPSD daemon by killing the process:
  

fnsysctl killall httpsd 

Or, with PID: 

diagnose sys process pidof httpsd

diagnose sys kill 11 <pid>

The process being killed can be verified by running 'diagnose debug crashlog read' and confirming the output, or by checking if the httpsd has a new process ID in the output of 'fnsysctl ps'.
If the issue persists, collect the output of the debug logs specified below, and consult the browser debugger tool output to help troubleshoot the problem.

Collect these outputs while reproducing the issue:

diagnose debug reset

diagnose debug application httpsd -1                      

diagnose debug console timestamp enable

diagnose debug enable

To disable debugging:

diagnose debug disable
diagnose debug reset

Check whether the HTTPSD process is crashing or not with the CLI command 'diagnose debug crashlog read'. 

Restarting the HTTPS daemon process by the engineer will result in a crash, which will be present in the 'diagnose debug crashlog read' output; therefore, when the issue is troubleshooted, these crashes caused by restart can be ignored. 

Note:

If the issue is not resolved, it is recommended to contact FortiGate support for further assistance.

Related article:

Troubleshooting Tip: Collect GUI slowness and errors debugs via Fortinet Support Tool