after a recent update I get this error

Failed to load mods: Warheads/prototypes/basegame-weapontype-add.lua19: attempt to index field '?' (a nil value)
stack traceback:
Warheads/prototypes/basegame-weapontype-add.lua19: in main chunk
[C]: in function 'require'
Warheads/data.lua:2: in main chunk

Mods to be disabled:
Warheads (0.0.14)

that is the error that shows up while trying to load with warheads enabled, I've tried removing mods that might have conflicted with no luck and have also tried deleting and redownloading the mod. Please help if possible

OK, thats pretty weird.
What version of the game are you using, and do you have any other weapon mods installed?

It looks like something is different with the shotgun shells...

sorry for the late reply, I am using version 1.1.76 (Build 60350, win64)
I am using Additonal turrets, Akimbo Vanilla Weapons, Armoured Train, Artillery Spidertron, Bigger Artillery, Cannon Spidertron, Broodmother, Combat Mechanics Overhaul, Firework Rockets + Assets Pack, Gun Equipment, Howitzer Cannon, Laser Weapons, Light Artillery (Balanced), Military 5, Modular Turrets, Orbital Ion Cannon (SE Edition), Portable GAU-8A Avenger mini, Rampant Arsenal, Robot Army, RoboTank, True Nukes.
yes that is a lot I'm disabling them 1 by 1 to see if that will fix it

I found out which mod was conflicting, The Tracer Ammuntion mod adds a few shotgun shells to the game which I didn't realise where there, it loads just fine without tracer ammo, sorry for the confusion, thank you for your help

OK, the issue was a little more subtle - Rampant arsenal and tracer ammo don't really like each other very much, but it doesn't quite cause an issue, but warheads gets tripped up by the combo.
Anyway, try 0.15 - should work with both now.