[Mythic Mobs] - Nikola Boss Pack

Please tell me where such a skill mechanics error knocks out every time.

[20:44:32 ERROR]: [MythicMobs] [SCHEDULER] Exception thrown whilst executing task
[20:44:32 WARN]: java.lang.NoSuchMethodError: org.bukkit.block.Block.isPassable()Z
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.util.BlockUtil.isPathable(BlockUtil.java:41)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.skills.mechanics.ProjectileMechanic$ProjectileMechanicTracker.projectileTick(ProjectileMechanic.java:227)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.skills.projectiles.Projectile$ProjectileTracker.run(Projectile.java:406)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.skills.projectiles.Projectile$ProjectileTracker.lambda$start$12(Projectile.java:383)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.Delegates$RunnableToFunction.apply(Delegates.java:189)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.promise.LuminePromise$ApplyRunnable.run(LuminePromise.java:684)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.tasks.LumineExecutors$SchedulerWrappedRunnable.run(LumineExecutors.java:70)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.promise.LuminePromise.executeSync(LuminePromise.java:133)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.promise.LuminePromise.lambda$thenApplySync$1(LuminePromise.java:364)
[20:44:32 WARN]: at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
[20:44:32 WARN]: at java.util.concurrent.CompletableFuture.uniWhenCompleteStage(CompletableFuture.java:792)
[20:44:32 WARN]: at java.util.concurrent.CompletableFuture.whenComplete(CompletableFuture.java:2153)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.promise.LuminePromise.thenApplySync(LuminePromise.java:360)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.utils.promise.Promise.thenRunSync(Promise.java:1019)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.skills.projectiles.Projectile$ProjectileTracker.start(Projectile.java:346)
[20:44:32 WARN]: at io.lumine.xikage.mythicmobs.skills.mechanics.ProjectileMechanic$ProjectileMechanicTracker.<init>(ProjectileMechanic.java:88)