I'm getting errors in my log from this plugin:

[nuttapillar]

[08:34:36] [Server thread/ERROR]: Could not pass event BlockBreakEvent to FarmingUpgrade v1.7.0 -- 3470 | java.lang.IllegalArgumentException: Material AIR is not harvestable. 3471 | at no.hyp.farmingupgrade.FarmingUpgradePlugin$ToolUpgrade.seeds(FarmingUpgradePlugin.java:396) ~[farmingupgrade-1.7.0.jar:?] 3472 | at no.hyp.farmingupgrade.FarmingUpgradePlugin.initiateHarvest(FarmingUpgradePlugin.java:489) ~[farmingupgrade-1.7.0.jar:?] 3473 | at no.hyp.farmingupgrade.FarmingUpgradePlugin.onFarm(FarmingUpgradePlugin.java:471) ~[farmingupgrade-1.7.0.jar:?] 3474 | at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor1169.execute(Unknown Source) ~[?:?] 3475 | at org.bukkit.plugin.EventExecutor$2.execute(EventExecutor.java:77) ~[pufferfish-api-1.20.4-R0.1-SNAPSHOT.jar:?] 3476 | at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:77) ~[pufferfish-api-1.20.4-R0.1-SNAPSHOT.jar:git-Pufferfish-45] 3477 | at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[pufferfish-api-1.20.4-R0.1-SNAPSHOT.jar:?] 3478 | at io.papermc.paper.plugin.manager.PaperEventManager.callEvent(PaperEventManager.java:54) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3479 | at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.callEvent(PaperPluginManagerImpl.java:126) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3480 | at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:617) ~[pufferfish-api-1.20.4-R0.1-SNAPSHOT.jar:?] 3481 | at net.minecraft.server.level.ServerPlayerGameMode.destroyBlock(ServerPlayerGameMode.java:375) ~[?:?] 3482 | at net.minecraft.server.level.ServerPlayerGameMode.destroyAndAck(ServerPlayerGameMode.java:334) ~[?:?] 3483 | at net.minecraft.server.level.ServerPlayerGameMode.handleBlockBreakAction(ServerPlayerGameMode.java:272) ~[?:?] 3484 | at net.minecraft.server.network.ServerGamePacketListenerImpl.handlePlayerAction(ServerGamePacketListenerImpl.java:1852) ~[?:?] 3485 | at net.minecraft.network.protocol.game.ServerboundPlayerActionPacket.handle(ServerboundPlayerActionPacket.java:42) ~[?:?] 3486 | at net.minecraft.network.protocol.game.ServerboundPlayerActionPacket.a(ServerboundPlayerActionPacket.java:15) ~[?:?] 3487 | at net.minecraft.network.protocol.PacketUtils.lambda$ensureRunningOnSameThread$0(PacketUtils.java:54) ~[?:?] 3488 | at net.minecraft.server.TickTask.run(TickTask.java:18) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3489 | at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:153) ~[?:?] 3490 | at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24) ~[?:?] 3491 | at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1462) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3492 | at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:194) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3493 | at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:126) ~[?:?] 3494 | at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1439) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3495 | at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1362) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3496 | at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:136) ~[?:?] 3497 | at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:1340) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3498 | at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1229) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3499 | at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:320) ~[pufferfish-1.20.4.jar:git-Pufferfish-45] 3500 | at java.lang.Thread.run(Thread.java:840) ~[?:?]

[Torm]

Hey, thanks for the report.
I have seen this bug reported a few times but I have not been able to figure out the cause. It seems that this happens only on Purpur/Pufferfish servers. Do you notice any unexpected behaviour when using the plugin?