[04:09:23] [Server thread/ERROR]: Could not pass event PlayerInteractEvent to ChestSell v1.0.0
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:319) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:589) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:576) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at org.bukkit.craftbukkit.v1_15_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:449) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.PlayerInteractManager.a(PlayerInteractManager.java:441) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:1251) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:27) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.MinecraftServer.ba(MinecraftServer.java:918) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:911) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:895) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:828) [spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_251]
Caused by: java.lang.NullPointerException
        at me.titus.listener.ChestInteractEvent.onBlockInteract(ChestInteractEvent.java:175) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_251]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_251]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_251]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:315) ~[spigot-1.15.2.jar:git-Spigot-2040c4c-77fd87e]
        ... 19 more