Verified that it is indeed LTN Combinator that is the problem.

Error message:

Error while loading gui-style prototype "default" (gui-style): Parent style not found: ltnc_misc_slot_selected

I have a fix:

LTN_Combinator_X.X.X\prototypes\styles.lua, line 60:

replace "selected_logistic_slot_button" with "slot_button"

LTN_Combinator_X.X.X\scripts\ltnc-gui.lua, line 916:

replace "large_caption_label" with "heading_3_label"

Both of these fixes make the mod work, as far as I can tell, however the style may not be exactly as Dockmeister intends.

Reference: https://forums.factorio.com/viewtopic.php?p=495184#p495184

also reminder, it wont work in multi

What is the problem that it doesn't works in multiplayer on a dedicated, headless server?

Also here is an image of the bug: https://i.imgur.com/EpwHd07.png

So, that's actually the same error that I fixed above (different parent styles, though). It seems odd that it only manifests in multiplayer. If you check the lua, and replace "misc_slot_selected" with "slot_button", it should work. It just may look a little strange.

Thanks for posting this fix - it works a treat in SP. <3

@chaos, in multi, mod checksum their value (to prevent desynch)

the server don't send the custom mod to the client, so the only way is to manually share the mod update with the client user