Hi, just got a crash when loading Factorio:

  27.657 Error ModManager.cpp:1625: Failed to load mod "zombie_engineer": __zombie_engineer__/prototypes/zombie-engineer.lua:10: bad argument #1 of 2 to 'pairs' (table expected, got nil)
stack traceback:
  [C]: in function 'pairs'
  __zombie_engineer__/prototypes/zombie-engineer.lua:10: in main chunk

Changing line 10 of prototypes/zombie-engineer.lua to this should fix the crash:

for _, layer in pairs(meleeAttackAnimation.layers or {}) do

When the crash occurred, Invisible Character was active, I suppose that mod removed the animations.

Any mods that add other characters are unsupported.
This will be on the main description after its next update.
These initial mod versions were rushed out to allow an experimental play-through with the mod.

Any mods that add other characters are unsupported.

That mod doesn't add a new character but modifies data.raw.character.character directly, so I think you should cover this.

Would lead to invisible zombies...
I will just expand the unsupported criteria and blacklist that mod.

I don't get why that mod exists tbh, but meh.

Would lead to invisible zombies...
I will just expand the unsupported criteria and blacklist that mod.

That's one way to deal with it. :-)

I don't get why that mod exists tbh, but meh.

Neither do I, but I really don't care. You see, some time ago some people decided they'd need a female character for better immersion, so they've got Gear Girl. Then somebody wanted to be able to switch characters during the game, or -- more generally -- allow players in a multiplayer game to choose whatever character they want. The technical aspect of it was interesting enough for me to come up with a character selector mod, and now there are something like 30 or 40 different characters available with other mods. I don't need a female, anime, furry, fish, etc. character myself, but obviously there are people who do feel strongly about them. Personally, I also don't understand why anybody would want to use an invisible character instead of playing in god mode. But what do I care -- even if invisible, it's still a character!

Any mods that add other characters are unsupported.

Is that set in stone? I believe it would be worthwhile to make our mods (Zombie Engineer and miniMAXIme) compatible. My mod creates already copies of the available characters to accommodate Bob's Character Classes and Jetpack. If your mod is active, I could create new Zombie Engineers as well. (As far as I can see, you just reuse a slowed-down version of the default character's animation.) If your mod wants to create a Zombie, its name should be derived from the character -- I could easily add a remote function that would return the name of a Zombie that matches the base name of the player's character. Would you be interested in that?

I don't plan on ever having dedicated graphics, unless someone else magically provides a full set.
This mod was meant to be made purely for a Multiplayer playthrough during Halloween and November; And would then be abandoned until next year probably.
Now it's taking far longer due to various reasons, but the overall plan is it's a one and done type thing.

Dealing with modded versions of things is a trap. At present the know traps are:
- modded characters.
- slowdown capsules and weapons with that effect.
- modded forces for both player and enemies, possibly with enemies being enemy to each other as well.
- modded entities that the zombie's should path around rather than go through, i.e. like spawners and nature at present.

When I was doing a previous mod "Careful driver" trying to deal with compatibility with other mods reported by yourself and others sucked the enjoyment out of working on that mod. It was abandoned as a direct result.
https://mods.factorio.com/mod/careful_driver

So from now on I do not plan to offer default support for other mods weird stuff when I myself am fighting with Factorio engine to do weird stuff.
If once my mod gets developed enough and is more commonly used then I will look at enhancements to enable compatibility with popular mods. But otherwise it is just premature optimisation.

I could either spend my time today adding new core features to make the zombies more fun to play with, or I could spend it trying to work out how to handle some custom character mods.