A zombie that has stopped is almost never broken. It is waiting on one of a short list of conditions, and the game tells you which one by saying nothing at all.
Every cause below is a rule the worker loop applies before it will lift a finger. They are listed in the order they bite, so start at the top.
A crafter makes one item and then stops forever
This is the one that catches everyone. A crafter finishes its recipe, the finished item goes into its own pockets, and the game raises a pickup order against it.
On the next tick the zombie sees it is holding an unexecuted order and switches itself off. It will stand at that bench until somebody takes the item away, and nothing else clears the order.
With no hauler in the zone a crafter produces exactly one of whatever you queued and then idles permanently. It looks like the recipe finished and the zombie lost interest.
The fix is a 
Zombie Supplier Station, which is four 
Wooden Plank and four 
Bronze Nails. Put one in the same zone and a caretaker appears to clear the bench.
The bench does tell you, in a way that is easy to misread. A blue sign appears above it carrying a figure with a box and a red line struck through, which is the Zombie Supplier Station’s own build icon crossed out. It shows only while a job is queued and waiting, so seeing it confirms the queue is fine and the delivery is the missing half.
Supply crates are the exception, and they are why the problem is so easy to miss. Anything in the 
Crate group is dropped on the floor instead of raising an order, so the bench restarts itself and the crate lines look like they are working properly while everything else has seized.
Four things a crafter checks before it starts at all
If the bench never begins in the first place, the zombie is failing one of four tests. There has to be a recipe queued at the bench, and it has to be a recipe the zombie can physically perform.
It needs the right kind of tool in its hands, and the station decides which kind. A bench that wants a 
Bronze Hammer is not satisfied by a zombie holding a 
Bronze Axe, however good the axe is.
The zombie’s mastery in that station’s track has to be at or above the recipe’s lock before it will accept the job. There is no slow version and no partial credit: below the lock it never starts.
Star crafts, autopsies, pocket extractions and studies skip the check entirely, which is why a zombie that refuses one recipe at a bench will happily run another at the same bench.
Then it checks the ingredients. For every one it is not already holding it raises a delivery order, stops its own work activity and waits. Those deliveries are the next thing to go wrong.
A delivery needs the whole amount, in the right container
A hauler will not take a delivery order until the full quantity exists in the zone. Nine planks against a recipe that wants ten produces no delivery at all, and nothing on screen says why.
The count is also only taken from storages whose contents list admits that item. Ten planks in a 
Simple Chest that does not accept planks are invisible to the arithmetic, so the bench starves next to a full container.
A caretaker subscribes to the orders of the zone it is standing in and no other. A bench in the yard is not served by a station in the garden, however short the walk looks on the map.
So every production zone needs its own hauler, and materials have to be in that zone before the bench will see them.
Caretakers fetch output before they fetch input
Orders are ranked, and the ranking is fixed. Planting outranks everything at ten, collecting finished goods sits at one, and delivering materials to a bench comes last at zero.
That produces the scene everybody recognizes. A bench sits on “waiting for materials” while a caretaker walks straight past it to collect somebody else’s output from the other end of the yard.
Adding more haulers helps less than it should. Only one caretaker can work a chest at a time, each pickup takes two seconds, and any other caretaker that comes within two meters of a chest in use force stops where it stands and waits its turn.
Gardeners need a shovel, and the better one blocks the worse
A gardener with an empty hand does not look for work. It does not walk the beds, it does not queue, it returns to its stand, and it stays there until you give it a shovel.
The tool has to be a shovel specifically. Any other tool leaves it as idle as an empty hand, so a 
Bronze Shovel is the cheapest fix for a garden that has stopped producing.
While a gardener with higher green mastery is idle at its stand in the same zone, every other gardener there is barred from taking a harvest order. The weaker one will plant all day and never pick anything.
Planting is unaffected and outranks harvesting anyway, so the symptom is beds that fill up, ripen and then sit there.
The three states the game will not name
Workers carry an internal state, and three of them mean stopped. None of the three is shown to you in words, so knowing what they are is most of the diagnosis.
The first is a failed path. Something has been built, dropped or parked across the route and the zombie could not reach its target, so it retries once a second and does nothing in between. Move whatever is in the way and it recovers on its own.
The second is nowhere to put the thing it is carrying. The third is queueing behind another caretaker at a chest. Both clear themselves the moment space or the chest frees up.
Conveyor zones fail differently and all at once. Power is counted against the tiles you have laid, and a 
Conveyor Belt, an 
Underground Conveyor, a 
Conveyor Splitter and a station tile each count one. Going a single tile over budget stops every belt, every autocrafter and every conveyor zombie in that zone together.
A porter ships with everything switched off
Porter stations work differently and carry two traps of their own. Every item a station can move starts disabled, and no station in the game ships with a default, so a freshly built one sends its zombie nowhere until you open it and tick something.
The second trap is capacity. A porter carries four slots, a large item eats two of them, and the station fills those slots walking its item list in a fixed order from the top.
The 
Lifting Crane lists wheat, carrots, beets, cabbage, onions and pumpkins ahead of it. With four slots filled from the top, 
Flax only moves on a trip where nothing above it had any stock.
If one crop never seems to reach your storage, check where it sits in the station’s list before you check anything else.
Raising a zombie’s mastery, which is a tool and nothing else
A zombie arrives with zero in all five tracks. Open its sheet and the row of colored numbers reads zero across the board, which is why a fresh worker will not touch anything above lock one no matter which bench you stand it at.
Put a tool in its equipment slot and the number moves immediately. A Bronze Axe is worth two, and the sheet goes from zero to two in the orange track the moment it lands, with no craft, no research and no waiting.
Thirty six tools in the game carry a bonus and they follow one ladder: rusty is one, bronze is two, iron is four and steel is six. A Master Rod at eight is the only thing above that line.
The color has to match the bench, which is where most of the confusion lives. Axes and pickaxes are orange for Building, hammers and the tool sets are red for Smithing, shovels and fishing rods are green for Farming, talismans and the reading books are yellow for Book writing, and the surgeon and alchemist kits are blue for Anatomy.
The Zombie tools perk gives a worker double the talent from whatever it is holding. A Bronze Axe stops being worth two and becomes four, which is the same as handing it an Iron Axe worth a thousand coins.
Take it before you buy metal. It applies to every zombie and every track at once, and it is the cheapest mastery in the game by a wide margin.
Above the tool sit the zombie’s own perks, and those are gated by its body rather than by you. The red skulls on its sheet are the perk slots, so a corpse that came out of the autopsy table with three red skulls can hold three perks and a poorer one cannot.
Two of your own perks reach every zombie at once. Motivator gives all of them plus one to all five tracks, and Zombie teacher makes them improve faster, so both apply across the whole workforce rather than to a single worker.
Those perks are worth more than the tool at the bench they name. Master Blacksmith is six red while working at an anvil, Master Carpenter is four while working with wood, and Grave architect is four orange on gravestones and fences. A zombie with the right perk and a bronze tool will out-work one carrying steel and nothing else.
Things that are never the reason
Half the usual suspects do not exist here. Zombies spend no energy, gain no insanity, never get hungry and never sleep, so a tired worker is not a thing that can happen.
Tools do not wear out either. Not one item in the game has durability at all, so no zombie has ever downed tools because its Bronze Axe broke.
Nor do zombies decay, so one that worked last week has not rotted in the meantime. If a worker has stopped it is one of the rules above, and the technology points it was earning stopped with it.
Graveyard Keeper 2 zombie workers FAQ
Why did my zombie only make one item?
Because the finished item raised a pickup order against the zombie and a crafter switches itself off while it holds one. Build a Zombie Supplier Station in the same zone and a caretaker will clear the bench.
Why is my zombie standing still at a workbench?
Either the bench has no recipe queued, the zombie is holding the wrong kind of tool, its mastery is below that recipe’s lock, or it is waiting on a delivery that cannot be taken because the full amount is not in the zone.
Why is my gardener not harvesting?
A gardener with no shovel never looks for a job at all. If it has one, a gardener with higher green mastery idling in the same garden blocks it from every harvest order while leaving planting alone.
Why do my zombies ignore a bench that needs materials?
Collecting output is priority one and delivering materials is priority zero, so a caretaker will always clear finished goods first. More caretakers helps only to a point, because one chest can serve one of them at a time.
Do zombies need food or rest in Graveyard Keeper 2?
No. They spend no energy, gain no insanity, never eat and never sleep, and their tools do not wear out because nothing in the game has durability.
Why did my porter station stop moving anything?
Every item at a porter station starts switched off, so a new one moves nothing until you tick items in it. Past that, a porter has four slots and fills them from the top of its list, so items low on the list get left.
