There is a line of code in BIS_fnc_Arsenal since 1.64 that is not needed and has made it so that you cannot Preload the arsenal data at mission load using
[ "Preload" ] spawn BIS_fnc_arsenal;
From fn_arsenal.sqf header
"Preload" - Preload item configs for Arsenal (without preloading, configs are parsed the first time Arsenal is opened)
No params
At line 949 you will find this..
//--- Magazines private _ctrlList = _display displayctrl (IDC_RSCDISPLAYARSENAL_LIST + IDC_RSCDISPLAYARSENAL_TAB_CARGOMAGALL);
If calling "Preload" as mentioned above _display is undefined.
This line has no use here and is erroneous as all the display elements are handled later in the process by "ListAdd" where the ctrl element is redefined as it iterates through the arsenal data at line 1080..
{
_ctrlList = _display displayctrl (IDC_RSCDISPLAYARSENAL_LIST + _foreachindex); <<<redefine of _ctrlList
_list = +_x; <<<Arsenal data index
....
switch _foreachindex do {
.....
case IDC_RSCDISPLAYARSENAL_TAB_CARGOMAGALL; <<<fill cargo mag list
case IDC_RSCDISPLAYARSENAL_TAB_CARGOTHROW;
case IDC_RSCDISPLAYARSENAL_TAB_CARGOPUT: {
_virtualCargo = _virtualMagazineCargo;
_virtualAll = _fullVersion || {"%ALL" in _virtualCargo};
_columns = count lnbGetColumnsPosition _ctrlList;
{
if (_virtualAll || {_x in _virtualCargo}) then {
_xCfg = configfile >> "cfgmagazines" >> _x;
_lbAdd = _ctrlList lnbaddrow ["",gettext (_xCfg >> "displayName"),str 0];
_ctrlList lnbsetdata [[_lbAdd,0],_x];
_ctrlList lnbsetpicture [[_lbAdd,0],gettext (_xCfg >> "picture")];
_ctrlList lnbsetvalue [[_lbAdd,0],getnumber (_xCfg >> "mass")];
_ctrlList lbsettooltip [_lbAdd * _columns,gettext (_xCfg >> "displayName")];
};
} foreach _list; <<<iterate magazine data
};