Attachments don't load on dedicated server

[old-df38257622]

On my dedicated server, during startup, I get a million lines of this:
!!!! Attachment <x>.lua has errors! lua/arccw/shared/sh_loadatts.lua:36: attempt to index a nil value
One for seemingly every attachment. Ingame, no attachments spawn/are visible when applied to the gun, including default ones like the stock. I'm using the entire ArcCW collection from Steam. The server addon collection is here: https://steamcommunity.com/sharedfiles/filedetails/?id=3240260960

The line that causes the error:
https://github.com/HaodongMo/ArcCW/blob/a268cde1a6f9e1a99e702d7524ace91fdf37609b/lua/arccw/shared/sh_loadatts.lua#L36

I also have these as filesystem addons:
https://github.com/LittleBigBug/chat-cosmetics
https://github.com/hoksalot/gm-psi
https://github.com/ZionDevelopers/sui-scoreboard

[old-df38257622]

Update: After some testing, this seems to happen without the filesystem addons. This issue also doesn't occur on a local, multiplayer listen server with only the same addon collection installed

[old-df38257622]

This happens having only ArcCW and any addon that provides any attachments installed. Guns seem to work fine (except some seemingly random exceptions which crash the server,) but attachments will always be broken this way. This persists after completely deleting and reinstalling the server, installing only ArcCW base and any addon like Gunsmith Offensive or Apex Legends SWEPs.

[Fesiug]

It's super strange and unknown how or why this happens, but there's a convar that allows you to disable generating of these attachment entities (arccw_reloadatts_registerentities) as a workaround.