error

[19:56:27 WARN]: [BossBarHealth] Task #15129193 for BossBarHealth v4.1.6-SNAPSHOT generated an exception
java.lang.NullPointerException: Cannot invoke "org.bukkit.entity.Player.getHealth()" because "player" is null
        at to.epac.factorycraft.bossbarhealth.hpbar.HealthBar.update(HealthBar.java:128) ~[BossBarHealth-4.1.6-SNAPSHOT.jar:?]
        at to.epac.factorycraft.bossbarhealth.hooks.WorldGuard.WgRegionHandler.lambda$onRegionEntered$0(WgRegionHandler.java:28) ~[BossBarHealth-4.1.6-SNAPSHOT.jar:?]
        at org.bukkit.craftbukkit.v1_18_R2.scheduler.CraftTask.run(CraftTask.java:101) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at org.bukkit.craftbukkit.v1_18_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:483) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1568) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at net.minecraft.server.dedicated.DedicatedServer.tickChildren(DedicatedServer.java:532) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1491) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1250) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at net.minecraft.server.MinecraftServer.lambda$spin$1(MinecraftServer.java:320) ~[mirai-1.18.2.jar:git-Mirai-Purpur-bbbb202]
        at java.lang.Thread.run(Thread.java:833) ~[?:?]