I run an ATM10 server, and every once in a while when I'm not looking, it chooses to crash. I can't personally read crash logs, so I uploaded it onto mclo.gs and sent some of it through ChatGPT (I am inept, sue me sob). It suggested the crash may be due to CosmeticArmorReworked "The server is stuck writing (and flushing) to your log file via Log4j’s RollingRandomAccessFileManager. On a player logout event, cosmeticarmorreworked’s InventoryManager.saveInventory runs synchronously on the main thread, doing file I/O (and logging) before tick completion.", so I opted to check with this github if anyone were so inclined to help, I would be grateful :)

Here are my crash logs:
https://mclo.gs/BlqLiWt

And here is the latest.log:
https://mclo.gs/9p8PuhE

To addon, I added Neruina, a mod that tries to prevent ticking crashes by forcibly stopping the cause, while playing I got kicked from the server by it with the following present in the logs:

When a ticking exception occurs on a normal Entity Neruina will kill it to prevent the server from crashing, but if that Entity happens to be a player, it will kick them instead. If you weren't kicked the server would have crashed.
[03Jun2025 18:54:38.835] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: HorizonP579 left the game
[03Jun2025 18:54:39.259] [Server thread/FATAL] [lain.mods.cos.init.neoforge.NeoForgeCosmeticArmorReworked/]: Failed to save CosmeticArmor data
java.nio.file.NoSuchFileException: ./world/playerdata/92afcef0-68b8-4fdf-b952-0215f970af72.cosarmor
at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92) ~[?:?]
at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:106) ~[?:?]
at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111) ~[?:?]
at java.base/sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:261) ~[?:?]
at java.base/java.nio.file.spi.FileSystemProvider.newOutputStream(FileSystemProvider.java:482) ~[?:?]
at java.base/java.nio.file.Files.newOutputStream(Files.java:227) ~[?:?]
at TRANSFORMER/[email protected]/net.minecraft.nbt.NbtIo.write(NbtIo.java:91) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/lain.mods.cos.impl.InventoryManager.saveInventory(InventoryManager.java:307) ~[cosmeticarmorreworked-1.21.1-v1-neoforge.jar%23636!/:?]
at TRANSFORMER/[email protected]/lain.mods.cos.impl.InventoryManager.handlePlayerLoggedOut(InventoryManager.java:196) ~[cosmeticarmorreworked-1.21.1-v1-neoforge.jar%23636!/:?]
at MC-BOOTSTRAP/net.neoforged.bus/net.neoforged.bus.ConsumerEventHandler.invoke(ConsumerEventHandler.java:26) ~[bus-8.0.2.jar%2362!/:?]
at MC-BOOTSTRAP/net.neoforged.bus/net.neoforged.bus.EventBus.post(EventBus.java:350) ~[bus-8.0.2.jar%2362!/:?]
at MC-BOOTSTRAP/net.neoforged.bus/net.neoforged.bus.EventBus.post(EventBus.java:315) ~[bus-8.0.2.jar%2362!/:?]
at TRANSFORMER/[email protected]/net.neoforged.neoforge.event.EventHooks.firePlayerLoggedOut(EventHooks.java:888) ~[neoforge-21.1.172-universal.jar%23549!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.players.PlayerList.remove(PlayerList.java:359) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.network.ServerGamePacketListenerImpl.removePlayerFromWorld(ServerGamePacketListenerImpl.java:1215) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.network.ServerGamePacketListenerImpl.onDisconnect(ServerGamePacketListenerImpl.java:1204) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.network.Connection.handleDisconnection(Connection.java:643) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.network.ServerConnectionListener.tick(ServerConnectionListener.java:172) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1051) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.dedicated.DedicatedServer.tickChildren(DedicatedServer.java:317) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:917) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:707) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at TRANSFORMER/[email protected]/net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:267) ~[server-1.21.1-20240808.144430-srg.jar%23548!/:?]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]

Please help. Thanks <3

To be honest... I have no idea about your issue.
But usually, it shouldn't fail on writing files, because at that point it is already out of the game logic.
The external system, at this point would be the file system/operating system/etc. is responsible about this error.
Does this happen to other players? If not, I would suggest you to tell your server operator about this and try looking into your player data, check file status/permission/etc.