| The mod loader's installer stopped with an errorinstaller_failed | Startup | fatal | 0 |
| The server could not download what it needs to startsource_download_failed | Startup | fatal | 0 |
| The server type does not offer the version the server asks forversion_not_available | Startup | fatal | 0 |
| The startup script refused a setting before downloading anythingstartup_invalid_parameter | Startup | fatal | 0 |
| Autopause could not be set up, so the server will not pause while idleautopause_failed | Startup | warning | 0 |
| The server runs an older Minecraft version than the latest releaseserver_version_outdated | Startup | warning | 0 |
| Java could not load an agent named in the server's Java optionsjava_agent_failed | Java | fatal | 0 |
| Java ran out of memory and the server stoppedout_of_memory | Java | fatal | 0 |
| The mod loader's installer needs a newer Java than the server hasinstaller_java_mismatch | Java | fatal | 0 |
| The server or a plugin needs a newer Java than the server runsjava_version_mismatch | Java | fatal | 0 |
| A plugin does not support this server versionplugin_unsupported_server | Plugins | error | 0 |
| A plugin fails while handling something in gameplugin_event_error | Plugins | error | 0 |
| A plugin loaded but failed to startplugin_enable_failed | Plugins | error | 0 |
| A plugin needs a setting before it can workplugin_not_configured | Plugins | error | 0 |
| A plugin needs another plugin that is not installedplugin_missing_dependency | Plugins | error | 0 |
| A plugin's file could not be loadedplugin_load_failed | Plugins | error | 0 |
| A plugin works better with a plugin that is not installedplugin_optional_dependency_missing | Plugins | warning | 0 |
| A mod could not change the game's codemixin_apply_failed | Mods | fatal | 0 |
| A mod made for players' games is installed on the serverclient_only_mod | Mods | fatal | 0 |
| A mod needs another mod that is not installedmod_missing_dependency | Mods | fatal | 0 |
| Two mods refuse to run togethermod_incompatible | Mods | fatal | 0 |
| Two threads used the same part of the world at once and the server stoppedthread_conflict | Mods | fatal | 0 |
| A mod failed while reacting to something in the gamemod_event_error | Mods | error | 0 |
| A player joined with versions of the server's mods that the server refusesclient_mods_mismatch | Mods | warning | 0 |
| The server was stopped as it came back from an idle pauseautopause_watchdog | Configuration | fatal | 0 |
| A mod's configuration file could not be readconfig_load_failed | Configuration | error | 0 |
| The loader rewrote configuration files that did not match what the mod expectsconfig_corrected | Configuration | warning | 0 |
| The server does not check players' accountsoffline_mode | Configuration | warning | 0 |
| The server started with autopause on and its watchdog still activeautopause_watchdog_enabled | Configuration | warning | 0 |
| The server froze and its watchdog stopped itserver_watchdog | Performance | fatal | 0 |
| The server used all of its container memory and was killedcontainer_oom_killed | Performance | fatal | 0 |
| The server fell behind and could not keep upserver_overloaded | Performance | warning | 0 |
| The server could not open its network portport_bind_failed | Network | error | 0 |
| Some game data of a datapack or mod did not loaddatapack_load_error | World and data | warning | 0 |
| A backend server turned the proxy's player away over player info forwardingproxy_forwarding_mismatch | Proxies | error | 0 |
| The proxy could not reach one of its backend serversproxy_backend_unreachable | Proxies | error | 0 |
| The database cannot read data written by another versiondatabase_version_mismatch | Databases | fatal | 0 |
| The database found damaged data on diskdatabase_corrupted | Databases | fatal | 0 |
| The database ran out of disk spacedatabase_disk_full | Databases | fatal | 0 |
| The database refused a login with a wrong user or passworddatabase_auth_failed | Databases | error | 0 |
| The server printed a problem the diagnosis does not recognise yetunclassified_exception · unclassified_error · unclassified_warning | Not recognised yet | error | 0 |