Cannot drop air

[EscolarProgramming]

Hello,
We have a problem with AutoPickup: It tries to drop air out of the inventory of the player, but that's impossible. Here's the stacktrace: https://hastebin.com/ciliyigipe

Server-Version: git-paper-186 (MC 1.16.2)
AutoPickup-Version: 5.4.0

[ThePhilderbeast]

Paper is not supported, please replicate on Spigot.

[ThePhilderbeast]

stacktrace has expired, posting one from the spigot site.

java.lang.IllegalArgumentException: Cannot drop air
com.google.common.base.Preconditions.checkArgument(Preconditions.java:122)
net.minecraft.server.v1_16_R2.EntityItem.setItemStack(EntityItem.java:454)
org.bukkit.craftbukkit.v1_16_R2.entity.CraftItem.setItemStack(CraftItem.java:35)
com.philderbeast.autopickup.util.Util.doFortune(Util.java:90)
com.philderbeast.autopickup.actions.LocationActions.doAutoActions(LocationActions.java:71)
com.philderbeast.autopickup.listners.MainListener.onItemSpawn(MainListener.java:304)
com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor906.execute(Unknown Source)
org.bukkit.plugin.EventExecutor.lambda$create$1(EventExecutor.java:69)
co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:80)
org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70)
org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:607)
org.bukkit.craftbukkit.v1_16_R2.event.CraftEventFactory.callItemSpawnEvent(CraftEventFactory.java:701)
org.bukkit.craftbukkit.v1_16_R2.event.CraftEventFactory.doEntityAddEventCalling(CraftEventFactory.java:596)
net.minecraft.server.v1_16_R2.WorldServer.addEntity0(WorldServer.java:1154)
net.minecraft.server.v1_16_R2.WorldServer.addEntity(WorldServer.java:1057)
org.bukkit.craftbukkit.v1_16_R2.event.CraftEventFactory.handleBlockDropItemEvent(CraftEventFactory.java:389)
net.minecraft.server.v1_16_R2.PlayerInteractManager.breakBlock(PlayerInteractManager.java:389)
net.minecraft.server.v1_16_R2.PlayerInteractManager.a(PlayerInteractManager.java:283)
net.minecraft.server.v1_16_R2.PlayerInteractManager.a(PlayerInteractManager.java:224)
net.minecraft.server.v1_16_R2.PlayerConnection.a(PlayerConnection.java:1385)
net.minecraft.server.v1_16_R2.PacketPlayInBlockDig.a(SourceFile:40)
net.minecraft.server.v1_16_R2.PacketPlayInBlockDig.a(SourceFile:10)
net.minecraft.server.v1_16_R2.PlayerConnectionUtils.lambda$ensureMainThread$1(PlayerConnectionUtils.java:23)
net.minecraft.server.v1_16_R2.TickTask.run(SourceFile:18)
net.minecraft.server.v1_16_R2.IAsyncTaskHandler.executeTask(IAsyncTaskHandler.java:136)
net.minecraft.server.v1_16_R2.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23)
net.minecraft.server.v1_16_R2.IAsyncTaskHandler.executeNext(IAsyncTaskHandler.java:109)
net.minecraft.server.v1_16_R2.MinecraftServer.ba(MinecraftServer.java:1135)
net.minecraft.server.v1_16_R2.MinecraftServer.executeNext(MinecraftServer.java:1128)
net.minecraft.server.v1_16_R2.IAsyncTaskHandler.awaitTasks(IAsyncTaskHandler.java:119)
net.minecraft.server.v1_16_R2.MinecraftServer.sleepForTick(MinecraftServer.java:1089)
net.minecraft.server.v1_16_R2.MinecraftServer.w(MinecraftServer.java:1003)
net.minecraft.server.v1_16_R2.MinecraftServer.lambda$a$0(MinecraftServer.java:177)
java.base/java.lang.Thread.run(Thread.java:834)```