Artifact console error

Could not pass event PlayerInteractEvent to MythicArtifacts v0.1.9-SNAPSHOT
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.11.2.jar:git-Spigot-a3f6ea5-a2af8f0]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.11.2.jar:git-Spigot-a3f6ea5-a2af8f0]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502)...

Artifact console error