500 Internal Server Error when accessing Cyberpanel Admin Port 8090 after upgrade to 2.4.3

I got 500 Internal Server Error when accessing Ubuntu installed Cyberpanel Admin Port 8090 after upgrade to 2.4.3. It looks like the cyberpanel database password has been corrupt after upgrade.

systemctl status mariadb shows mariadb is active running but gives the following error.
mariadb[1114]: 2025-08-13 10:02:22 3 [Warning] Access denied for user ‘root’@‘localhost’ (using password: NO)
/etc/mysql/debian-start [1227]: Reading datadir from the MariaDB server failed. Got the following error when executing the ‘mysql’ command line client
/etc/mysql/debian-start [1227]: ERROR 1045 (28000): Access denied for user ‘root’@‘localhost’ (using password: NO)
/etc/mysql/debian-start [1227]: FATAL ERROR: Upgrade failed
/etc/mysql/debian-start [1269]: Checking for insecure root accounts.
mariadb[1114]: 2025-08-13 10:02:23 4 [Warning] Access denied for user ‘root’@‘localhost’ (using password: NO)
debian-start [1280] : ERROR 1045 (28000): Access denied for user ‘root’@‘localhost’ (using password: NO)

The passwords are the same for the following file. I have rebooted the system and it still doesn’t work.
/usr/local/CyberCP/CyberCP/settings.py (both password the same as in the following file)
/etc/cyberpanel/mysqlPassword (only password)

How can I fix this database error? Any help is greatly appreciated.

you could try doing the upgrade again via ssh or through cyberpanel itself (if you can access). I have done this as my server stopped responding on the 18th but when I ssh’d in on the 22nd (yesterday) it went through and I can get to my cyberpanel via port 8090 but I can’t do anything else. My DNS is pointing the right way but itt will not allow me to apply the host SSL as it cannot be found. I hope a re-upgrade fixes all your problems - I am still waiting. Hopefully I will be awake when the next reply comes in.
Have a blessed day.