A plugin is still scheduling work after being disabled
Applies to Paper, Vanilla.
What it looks like in your log
org.bukkit.plugin.IllegalPluginAccessException: Plugin attempted to register task while disabled
What causes it
The plugin was disabled (a reload, a failed enable, or a shutdown) but code inside it still tried to schedule a task; Bukkit refuses and prints this stack. Harmless during shutdown, a symptom of a broken enable or a /reload while the server is running.
How to fix it
If it appears at shutdown, ignore it. If it appears while the server is running, the plugin failed to enable earlier: read the first error it printed at startup. Stop using /reload, which is what usually leaves plugins half-alive; restart instead.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log