Thanks a lot for taking the time to go through the logs and help me track this down :)
I suspect the issue happens because sometimes //dlcs//dlc_1//dlc_1_data_ext.gd gets loaded before the class it extends.
I just changed the load order so that //dlcs//dlc_1//dlc_1_data_ext.gd is the last extension to load — hopefully that’s enough.
If not, I’ll probably have to go with dynamic loading.
Please make sure you’ve got the latest version and give it another try; I can’t test it myself because the problem doesn’t show up on my devices.

Great mod, but weird error happens.
I don't know how to describe it, but it happens like this: open the game, cant use mod, reopen, everything is fine. I don't know why.

I remove all my mods and only subscribe the mod, but error still happens every second times I open the game.

Then I checked the log and found that there's a statement
extends "res://dlcs/dlc_1/dlc_1_data.gd"
in //dlcs//dlc_1//dlc_1_data_ext.gd.
The game's log tells that it didn't find the dlc_1_data.gd in dlc_1 and so as I, I think that might be the question.

I'm not a native English speaker, so I'm not sure if I expressed myself clearly. If there's any problems about my expressing, please point it out.

I can reproduce the problem when subscribing to both mods on Steam. However, when debugging with both mod files in Godot, everything works fine, which makes it really hard to track down the issue. Looking at the code, our extensions shouldn’t overlap in any case. For now, I wasn’t able to identify the root cause and I don’t think it’s worth putting hours into chasing down a compatibility issue. If the demand for combining both mods increases, I’ll take a closer look again.

Found the mod that it doesn't work with.

Brotatogether - Networked Multiplayer with Steam Lobbies

To be fair, I havn't tried this mod out myself but it has 5 Stars and I had downloaded it to play with a few friends whom never ended up playing with me anyways XD

@Blaze
I have never touched any spawning behavior of materials, consumables, or chests. Does this also happen when only this mod is installed?
If not, could you try to find out which mod is incompatible so I can troubleshoot the issue?

Not sure if this is interacting horribly with another mod but all my materials and items are spawning in the top left after installing this mod. Everything unobtainable and thus unplayable.

martyr is working now

The martyr isn't working properly yet. I uploaded him today and have no time to fix bugs anymore today.

@游戏而已,别怪罪队友
Thanks for the hint.
I let Al handle the translations for me, so it's hard for me to tell which names are already taken in each language

陷阱师砍树并不会生成炸弹
另外“叛徒”改名为“内奸”更合适，因为原版已经有一个“叛徒”了