When a plugin does not appear after a restart, the server almost always said why. The answer is in the startup log, in the seconds after the plugin's name.
What you are seeing
- The plugin is red in the
pluginslist, or missing from it entirely. - Its configuration folder was never created.
- Its commands return
Unknown command.
What to do
- Find the plugin's name in the startup log
Search the console output for it. Either it says it enabled, or there is an error next to it — and that error is the answer.
- Version mismatch
Unsupported API versionor a plain incompatibility message means the plugin was built for a different Minecraft version. Get the build that matches yours. - Missing dependency
The log names what it wanted in brackets. Install that first, then restart.
- Broken or partial file
Invalid plugin.ymlor a zip error means the jar is damaged, usually from an interrupted upload. Delete and re-upload it. - Wrong server type
If the console never mentions it at all, check you are not putting a plugin on a Forge server or a mod in
plugins.
plugins lists it in green and its commands respond.
A plugin that loads but does nothing is a different problem: it loaded, so look at its configuration file and its permissions rather than at the startup log.