[Emmet_]

Try this maybe?

pawn Код:

public OnPlayerUpdate(playerid)
{
    if(GetPlayerWeapon(playerid))
    {
        SetPlayerArmedWeapon(playerid, 0);
        return 0;
    }
    if(!IsPlayerInAnyVehicle(playerid))
    {
        return 0;
    }
    return 1;
}

Fact: Returning zero under OnPlayerUpdate will halt the sync, if the 'if' expression above is true.