it works fine for a friend, but refuses to work for me. heres the error, now how do i fix this!?

[21:06:36.813] [Error] Exception while invoking lua function 'update'. (LuaException) Error code 2, [string "/vehicles/modularmech/armscripts/base.lua"]:99: attempt to index a nil value (field 'parts')
stack traceback:
[C]: in metamethod '__index'
[string "/vehicles/modularmech/armscripts/base.lua"]:99: in method 'statSet'
[string "/vehicles/modularmech/armscripts/base.lua"]:152: in method 'fire'
[string "/vehicles/modularmech/armscripts/gatlingarm.l..."]:27: in method 'update'
[string "/vehicles/modularmech/modularmech.lua"]:565: in function <[string "/vehicles/modularmech/modularmech.lua"]:200>
[0] 7ff7866fa213 Star::captureStack
[1] 7ff7866f8f9e Star::StarException::StarException
[2] 7ff7866ccfb1 Star::LuaEngine::handleError
[3] 7ff7868aeba5 Star::LuaEngine::callFunction<float>
[4] 7ff7868b2896 Star::LuaFunction::invoke<Star::Variant<Star::Empty,bool,__int64,double,Star::LuaString,Star::LuaTable,Star::LuaFunction,Star::LuaThread,Star::LuaUserData>,float>
[5] 7ff7868b27c9 Star::LuaBaseComponent::invoke<Star::Variant<Star::Empty,bool,__int64,double,Star::LuaString,Star::LuaTable,Star::LuaFunction,Star::LuaThread,Star::LuaUserData>,float>
[6] 7ff7868ba44c Star::LuaUpdatableComponent<Star::LuaWorldComponent<Star::LuaBaseComponent> >::update<Star::Variant<Star::Empty,bool,__int64,double,Star::LuaString,Star::LuaTable,Star::LuaFunction,Star::LuaThread,Star::LuaUserData>,float>
[7] 7ff786bd85a6 Star::Vehicle::update
[8] 7ff786c03648 <lambda_9fc580ae40b93070d912cafafa15880e>::operator()
[9] 7ff786843846 Star::EntityMap::updateAllEntities
[10] 7ff786c1c15b Star::WorldClient::update
[11] 7ff786b869bd Star::UniverseClient::update
[12] 7ff786645da7 Star::ClientApplication::updateRunning
[13] 7ff78664473d Star::ClientApplication::update
[14] 7ff786e0d4d1 Star::SdlPlatform::run
[15] 7ff786e0d68d Star::runMainApplication
[16] 7ff786647731 WinMain
[17] 7ff786ff07af __scrt_common_main_seh
[18] 7ffc4b627bd4 BaseThreadInitThunk
[19] 7ffc4d0cced1 RtlUserThreadStart