Tried to get invalid ammunition: rebar_bolt

I’m trying to add a couple of vehicle-mounted railguns to my ForkIt mod, but it’s having trouble with this one type of ammunition, which is the default one.

The guns definition:

{
“id”: “emrail”,
“copy-from”: “rifle_semi”,
“looks_like”: “m2browning”,
“type”: “GUN”,
“name”: { “str_sp”: “electromagnetic railgun” },
“description”: “A mass driver that uses electromagnets to drive a sled on rails carrying a heavy payload, and launch the payload at high speed much like a slingshot. The sled is designed to carry payloads of a wide variety of shapes and sizes, up to about 20kg. Too heavy to be fired handheld, but can be mounted on a vehicle. Powered by UPS, and consumes 150 charges per shot.”,
“weight”: “38000 g”,
“volume”: “9020 ml”,
“longest_side”: “165 cm”,
“price”: 1800000,
“price_postapoc”: 10000,
“to_hit”: -1,
“bashing”: 12,
“material”: [ “steel” ],
“ammo”: [ “rebar_bolt” ],
“range”: 110,
“dispersion”: 150,
“durability”: 8,
“min_cycle_recoil”: 5,
“reload”: 250,
“ups_charges”: 150,
“modes”: [ [ “DEFAULT”, “semi-auto”, 1 ] ],
“flags”: [ “MOUNTED_GUN” ],
“pocket_data”: [
{
“pocket_type”: “MAGAZINE”,
“ammo_restriction”: { “rebar_bolt”: 1 }
}
]
},
{
“id”: “pnrail”,
“copy-from”: “rifle_semi”,
“looks_like”: “m2browning”,
“type”: “GUN”,
“name”: { “str_sp”: “pneumatic railgun” },
“description”: “A mass driver that uses compressed air stored by a high-pressure pump to drive a sled on rails carrying a heavy payload, and launch the payload at high speed much like a slingshot. The sled is designed to carry payloads of a wide variety of shapes and sizes, up to about 15kg. Too heavy to be fired handheld, but can be mounted on a vehicle. Consumes little energy, but takes a long time to reload between shots.”,
“weight”: “38000 g”,
“volume”: “9020 ml”,
“longest_side”: “165 cm”,
“price”: 1800000,
“price_postapoc”: 10000,
“to_hit”: -1,
“bashing”: 12,
“material”: [ “steel” ],
“ammo”: [ “rebar_bolt” ],
“range”: 110,
“dispersion”: 150,
“durability”: 8,
“min_cycle_recoil”: 5,
“reload”: 2400,
“ups_charges”: 15,
“modes”: [ [ “DEFAULT”, “semi-auto”, 1 ] ],
“flags”: [ “MOUNTED_GUN” ],
“pocket_data”: [
{
“pocket_type”: “MAGAZINE”,
“ammo_restriction”: { “rebar_bolt”: 1 }
}
]
}

They use several different types of ammo, but I’ve set it to just the one for debugging. However, even when I had all of them in, it was only the rebar_bolt that produced an error.

The ammo type definition:

{
“id”: “mass_driver”,
“type”: “ammunition_type”,
“name”: “mass driver projectile”,
“default”: “rebar_bolt”
}

The ammo definitions:

{
“id”: “cannon_slug”,
“type”: “AMMO”,
“name”: { “str_sp”: “cannon slug” },
“description”: “A roughly bullet-shaped 4 pound piece of steel, for use in a mass driver.”,
“//”: “Copied from the 4 pound cannonball, as it’s identical except for the shape and propellant, and muzzle velocity should be similar.”,
“weight”: “2350 g”,
“volume”: “1000 ml”,
“price”: 1100,
“price_postapoc”: 1200,
“material”: [ “steel” ],
“symbol”: “=”,
“color”: “white”,
“count”: 1,
“stack_size”: 1,
“ammo_type”: “mass_driver”,
“range”: 60,
“damage”: { “damage_type”: “bullet”, “amount”: 352 },
“//2”: “4 pound cannonball weighs 28000 grains,shot at 1215 ft/s by a 3in ordnance rifle, equals 124459 joules of muzzle energy according to Shooters Calculator, round down from square root 352.78”,
“dispersion”: 45,
“recoil”: 5,
“loudness”: 5,
“effects”: [ “RECYCLED” ]
},
{
“type”: “AMMO”,
“id”: “rebar”,
“symbol”: “/”,
“color”: “light_gray”,
“name”: { “str”: “rebar” },
“description”: “An 80cm length of nice straight rebar, for use in a mass driver.”,
“category”: “spare_parts”,
“price”: 7500,
“price_postapoc”: 25,
“material”: [ “steel” ],
“weight”: “1245 g”,
“volume”: “159 ml”,
“longest_side”: “80 cm”,
“bashing”: 10,
“to_hit”: -1,
“count”: 1,
“stack_size”: 1,
“ammo_type”: “mass_driver”,
“range”: 60,
“damage”: { “damage_type”: “bullet”, “amount”: 60 },
“dispersion”: 35,
“recoil”: 5,
“loudness”: 5,
“effects”: [ “RECYCLED” ]
},
{
“type”: “AMMO”,
“id”: “rebar_bolt”,
“symbol”: “/”,
“color”: “light_gray”,
“name”: { “str”: “rebar bolt” },
“description”: “A 20cm piece of rebar, sharpened on one end, for use in a mass driver. It flies much more stably than a full-sized piece of rebar, and is more likely to hit on-end, doing considerably more damage.”,
“category”: “spare_parts”,
“price”: 7500,
“price_postapoc”: 25,
“material”: [ “steel” ],
“weight”: “312 g”,
“volume”: “40 ml”,
“longest_side”: “20 cm”,
“bashing”: 10,
“to_hit”: -1,
“count”: 1,
“stack_size”: 1,
“ammo_type”: “mass_driver”,
“range”: 60,
“damage”: { “damage_type”: “bullet”, “amount”: 45, “armor_penetration”: 20 },
“dispersion”: 10,
“recoil”: 5,
“loudness”: 5,
“effects”: [ “RECYCLED” ]
},
{
“type”: “AMMO”,
“id”: “steel_lump”,
“symbol”: “o”,
“color”: “light_gray”,
“name”: { “str”: “lump of steel” },
“description”: “A 1kg lump of rough scrap steel, for use in a mass driver.”,
“category”: “spare_parts”,
“price”: 7500,
“price_postapoc”: 25,
“material”: [ “steel” ],
“weight”: “1000 g”,
“volume”: “126 ml”,
“longest_side”: “12 cm”,
“bashing”: 10,
“to_hit”: -1,
“count”: 1,
“stack_size”: 1,
“ammo_type”: “mass_driver”,
“range”: 60,
“damage”: { “damage_type”: “bullet”, “amount”: 35 },
“dispersion”: 45,
“recoil”: 5,
“loudness”: 5,
“effects”: [ “RECYCLED” ]
},
{
“type”: “AMMO”,
“id”: “ducart”,
“symbol”: “/”,
“color”: “light_gray”,
“name”: { “str”: “30mm du cartridge” },
“description”: “A 30x173mm cartridge loaded with a depleted uranium-cored HEDP projectile. If only you had an A10 Thunderbolt to fire it from. You could launch it with a mass driver, though, albeit much less effectively.”,
“category”: “spare_parts”,
“price”: 7500,
“price_postapoc”: 25,
“material”: [ “aluminum”, “du” ],
“weight”: “1215 g”,
“//3”: “395g projectile mass (from Wikipedia), 150g propellant mass (from General Dynamics), 670g cartridge mass (GD), 1215g total assuming that 670 is mass of brass alone. Otherwise, 125g brass.”,
“volume”: “40 ml”,
“longest_side”: “20 cm”,
“bashing”: 10,
“to_hit”: -1,
“count”: 1,
“stack_size”: 1,
“ammo_type”: “mass_driver”,
“range”: 60,
“damage”: { “damage_type”: “bullet”, “amount”: 60, “armor_penetration”: 15 },
“//4”: “The round isn’t being fired, but rather launched as from a slingshot, casing and all, at a lower (but still fairly high) velocity. The round is designed to punch through tank armour though, so it’s going to get at”,
“//5”: “least some penetration against vehicle armour, at least if it detonates, and should punch through any body armour like a .50bmg through butter.”,
“dispersion”: 15,
“recoil”: 5,
“loudness”: 5,
“effects”: [ “COOKOFF”, “EXPLOSIVE” ]
}

The du material definition, not that it’s relevant to the current issue.

{
“type”: “material”,
“id”: “du”,
“name”: “depleted uranium”,
“density”: 19.0,
“bash_resist”: 6,
“specific_heat_liquid”: 0.82,
“specific_heat_solid”: 0.45,
“latent_heat”: 273,
“cut_resist”: 6,
“bullet_resist”: 3,
“acid_resist”: 7,
“fire_resist”: 3,
“conductive”: true,
“chip_resist”: 20,
“dmg_adj”: [ “marked”, “dented”, “smashed”, “shattered” ],
“bash_dmg_verb”: “dented”,
“cut_dmg_verb”: “scratched”,
“burn_products”: [ [ “scrap”, 1 ] ],
“fuel_data”: { “energy”: “500 kJ” }
}

(it’s mostly just copied from regular uranium)

I assume the issue is a missing , or " or ) or a typo somewhere, but I’ve searched and searched, and can’t find anything.

It also gives a “missing item definition” error, but doesn’t say what item.