Am getting this error:

121.638 Error ModManager.cpp:1514: Failed to load mod "Devterevs_Warfare": Devterevs_Warfare/data-updates.lua:99: attempt to concatenate field '?' (a nil value)
stack traceback:
Devterevs_Warfare/data-updates.lua:99: in main chunk
121.641 Loading mod core 0.0.0 (data.lua)
122.050 Checksum for core: 3692526182
122.103 Error ModManager.cpp:1514: Error in assignID: recipe-category with name 'crafting' does not exist.

Source: default (utility-sprites).
122.205 Initial atlas bitmap size is 16384
122.208 Created atlas bitmap 2048x560 [icon, not-compressed, mipmap, linear-minification, linear-magnification, linear-mip-level]
122.216 Texture processor created (2048). GPU accelerated compression Supported: yes, Enabled: yes/yes. Test passed. YCoCgDXT PSNR: 35.83, BC3 PSNR: 33.82
122.341 Parallel Sprite Loader initialized (threads: 11)
122.807 Sprites loaded
122.834 Generated mipmaps (5) for atlas [0] of size 2048x560
122.834 Custom mipmaps uploaded.
122.837 Factorio initialised
122.841 Mods to disable:Failed to load mods: Devterevs_Warfare/data-updates.lua:99: attempt to concatenate field '?' (a nil value)
stack traceback:
Devterevs_Warfare/data-updates.lua:99: in main chunk

Mods to be disabled:
• Devterevs_Warfare (0.5.25)

Possible mod conflict

The question is where in the code, why, and how can it be fixed.

try turning off all mods and gradually turn them on with mine.
in this way you will find conflicting