Invalid Pointer in my EA

[Tawaz Malazoh]

My EA is compiling well, but when l try to run it in platform it return INVALID POINTER error

here is the code

//+------------------------------------------------------------------+

void Strategy::GetRequiredCharts(string &charts[])

  {

   ArrayResize(charts,1);

   charts[0]=GetSymbol()+","+DataPeriodToString(GetPeriod());

   for(int i=0; i<Slots(); i++)

     {

      if(!Slot[i].IndicatorPointer.IsAllowLTF)

         continue;

      if(!IsLongerTimeFrame(i))

         continue;

      string chart=GetSlotChart(i);

      if(!ArrayContainsString(charts,chart))

         ArrayAppendString(charts,chart);

     }

  }

//+------------------------------------------------------------------+

Any  help is welcome