The server does not match Zabbix database

[mike.capps]

Been having an issue where the zabbix-server service suddenly stops and won't start again in Ubuntu. When checking the zabbix_server.log file, the error message is:

"The server does not match Zabbix database. Current database version (mandatory/optional): 04000000/04000004. Required mandatory version: 03000000."

This is a working install of Zabbix 4.0 LTS, that has been running great for over a month and has thousands of items being monitored. No updates or upgrades have occurred. to both the application or the OS. This isn't the first time this has happened to me. Previously I've had to roll back to a checkpoint when it was working properly, but that is not an option this time around. And ideas?

[tim.mooney]

Are you sure you don't have some kind of automated process (like a configuration management system) that is running periodically and mistakenly resetting some of your package versions back to an older version?

The next time this happens, use your Ubuntu package management commands to display the installed version of all zabbix-related packages. Make sure none of them have been downgraded.