There are two ways to troubleshoot any problem while using Nexi Panel.
First Way of Troubleshooting Nexi Panel
There is a global error log file (this file only contains logs generated by Nexi Panel). This file can be reached at
https://<IP Address>:8090/serverstatus/cyberCPMainLogFile
Improved and detailed dynamic logging
/usr/local/CyberCP/debug
Run command:
touch /usr/local/CyberCP/debug
This will start generating more debug logs. If you find any issue with Nexi Panel, you can run this command and then capture the output of /home/Nexi Panel/error-logs.txt and share it with our support team.
/usr/local/CyberCP/emailDebug
If you want logs in /home/Nexi Panel/error-logs.txt to be emailed to you, please run touch /usr/local/CyberCP/emailDebug, and you will get logs in your email. (Email of admin account will be used to send these notifications.) This also includes a notification if Nexi Panel fails to obtain SSL for any domain.
Second Way of Troubleshooting Nexi Panel
If you can not find anything reasonable using the first way, then open your command-line terminal and run.
journalctl -f | grep lscpd
After running this command, return to the Nexi Panel and repeat the action that caused the issues, then return to the terminal and capture the output.

Find errors in email problems.
If, for some reason, your emails are not going through, you can use the commands below to capture the output and get to the bottom of the issue:
journalctl -f | grep postfix
(For email delivery issues)journalctl -f | grep dovecot
(For issues related to Rainloop Webmail)
Run these commands and then perform the operation that was causing the error, which will get you to the bottom of the problem. If you need our help, make sure to share the output logs depending on your support request.
Enable Django Debug Logs (To find out the reason for the 500 error on Nexi Panel)
nano /usr/local/CyberCP/CyberCP/settings.py
find DEBUG = False
and change it to DEBUG = True
and then do systemctl restart lscpd
And then redo what you are doing, and you will get the reason for the 500 Error