[04:21:23 FATAL]: Error executing task
java.lang.NullPointerException: null
        at net.minecraft.server.v1_13_R2.EntityPlayer.openSign(EntityPlayer.java:891) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.ItemStack.placeItem(ItemStack.java:316) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.PlayerInteractManager.a(PlayerInteractManager.java:537) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:1347) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.PacketPlayInUseItem.a(PacketPlayInUseItem.java:37) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.PacketPlayInUseItem.a(PacketPlayInUseItem.java:5) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.lambda$ensureMainThread$0(PlayerConnectionUtils.java:15) ~[patched_1.13.2.jar:git-Paper-605]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_201]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[?:1.8.0_201]
        at net.minecraft.server.v1_13_R2.SystemUtils.a(SystemUtils.java:108) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:1018) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:439) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:940) ~[patched_1.13.2.jar:git-Paper-605]
        at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:837) ~[patched_1.13.2.jar:git-Paper-605]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_201]