1.11.2 version problem with quest plugin

[01:54:30] [Server thread/ERROR]: Could not pass event MythicMobDeathEvent to Quests v2.7.5-b119
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[minecraft_server.jar:git-Spigot-7d78b81-50acb44]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[minecraft_server.jar:git-Spigot-7d78b81-50acb44]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502)...

1.11.2 version problem with quest plugin