Opening the terminal shows Connecting.. Error connecting to backend.. Connection Closed

I am trying to open the terminal in my admin panel, but when i do it it shows

Error connecting to backend.
Connection Closed

I tried rebot SSH server but that wont fix the issue for me

Same issue. Has anyone solved it?

Are you using ip to access or hostname with SSL?

I have faced this issue after rebooting the server using reboot command

Error connecting to backend.                                                                                            
connection closed .

Same problem, I am using IP and custom ssh port. But even with default 22 still error.
Firewall was open ssh port.

root@cyberpanel:/# ps aux | grep CPWeb
root 13530 0.0 3.0 53244 32268 ? S 11:50 0:00 /usr/local/CyberCP/bin/python /usr/local/CyberCP/WebTerminal/
root 13629 0.0 0.0 6432 724 pts/1 S+ 11:51 0:00 grep --color=auto CPWeb

We just installed cyberpanel on uBuntu 20.04.6 server, and encountered the same problem. We have tried all the suggestions (mentioned above), and followed the guidelines on this webpage (Web Terminal - CyberPanel), but we still can’t fix this error.

Welcome your suggestions and assistance. Thank you in advance for any assistance.