Error shows up in console:
[Tue, 17. Dec 2019 17:57:57 GMT INFO] Not using JDBC, one of host/port/database was default
[Tue, 17. Dec 2019 17:57:57 GMT WARN] java.lang.NoClassDefFoundError: org/bukkit/event/player/PlayerAchievementAwardedEvent
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at github.scarsz.discordsrv.listeners.PlayerAchievementsListener.<init>(PlayerAchievementsListener.java:35)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at github.scarsz.discordsrv.DiscordSRV.init(DiscordSRV.java:422)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at java.lang.Thread.run(Thread.java:748)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] Caused by: java.lang.ClassNotFoundException: org.bukkit.event.player.PlayerAchievementAwardedEvent
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:90)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:85)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
[Tue, 17. Dec 2019 17:57:57 GMT WARN] ... 3 more
[Tue, 17. Dec 2019 17:57:57 GMT WARN] You are running a development version, please report any bugs to GitHub.